CSLB General Building (B) — All Questions

A train travels at a constant speed of 60 miles per hour. How long will it take to travel 180 miles?

• a.3 hours✓
• b.2 hours
• c.3.5 hours
• d.4 hours

Time equals distance divided by speed. Dividing 180 miles by 60 miles per hour gives 3 hours. Keeping the units consistent lets the miles cancel and leaves hours.

If 5 pounds of apples cost $4.00, how much do 12 pounds cost at the same rate?

• a.$8.40
• b.$9.60✓
• c.$10.00
• d.$12.00

The unit price is $4.00 divided by 5 pounds, or $0.80 per pound. Multiplying $0.80 by 12 pounds gives $9.60. Setting up a proportion produces the same result.

What is 25% of 240?

• a.48
• b.72
• c.60✓
• d.80

Twenty-five percent is the same as one quarter. Dividing 240 by 4 gives 60. You could also multiply 240 by 0.25 to reach the same value.

A recipe uses flour and sugar in a ratio of 3 to 1. If you use 9 cups of flour, how many cups of sugar are needed?

• a.1 cup
• b.6 cups
• c.12 cups
• d.3 cups✓

The ratio 3 to 1 means three parts flour for every one part sugar. Since 9 cups of flour is three times the base part of 3, the sugar is also tripled from 1 to 3 cups. Ratios scale both quantities by the same factor.

The average of four test scores is 85. Three of the scores are 80, 90, and 85. What is the fourth score?

• a.85✓
• b.80
• c.90
• d.95

An average of 85 over four tests means the total is 85 times 4, or 340. The three known scores add to 255, so the fourth score is 340 minus 255, which equals 85.

A worker can assemble 8 units per hour. How many units can 3 workers assemble in 5 hours at that rate?

• a.40 units
• b.120 units✓
• c.80 units
• d.160 units

One worker makes 8 units per hour, so 3 workers make 24 units per hour. Over 5 hours that is 24 times 5, which equals 120 units. Rate times number of workers times time gives total output.

A jacket originally priced at $80 is discounted 15%. What is the sale price?

• a.$65
• b.$72
• c.$68✓
• d.$76

Fifteen percent of $80 is $12. Subtracting the $12 discount from $80 leaves a sale price of $68. You can also multiply $80 by 0.85 to get the same answer.

You deposit $500 in an account earning 4% simple interest per year. How much interest is earned in 3 years?

• a.$20
• b.$40
• c.$80
• d.$60✓

Simple interest equals principal times rate times time. That is $500 times 0.04 times 3, which equals $60. Simple interest is calculated only on the original principal.

Two cars start from the same point and drive in opposite directions at 40 mph and 55 mph. How far apart are they after 2 hours?

• a.190 miles✓
• b.95 miles
• c.110 miles
• d.150 miles

Their combined separation speed is 40 plus 55, or 95 miles per hour. After 2 hours they are 95 times 2, which equals 190 miles apart. Opposite directions mean the speeds add.

A map uses a scale of 1 inch to 25 miles. Two towns are 4.5 inches apart on the map. What is the actual distance?

• a.100 miles
• b.112.5 miles✓
• c.125 miles
• d.90 miles

Each inch represents 25 miles, so multiply 4.5 inches by 25 miles per inch. That product is 112.5 miles. Scale problems are solved with a direct proportion.

A rectangular room is 12 feet long and 9 feet wide. If carpet costs $3 per square foot, what is the total cost to carpet the room?

• a.$108
• b.$252
• c.$324✓
• d.$396

The floor area is length times width, or 12 times 9, which equals 108 square feet. Multiplying 108 square feet by $3 per square foot gives $324.

A store sells 6 bottles of water for $9. What is the cost of one bottle?

• a.$1.20
• b.$1.75
• c.$2.00
• d.$1.50✓

Dividing the total price of $9 by 6 bottles gives $1.50 per bottle. Unit price is found by dividing total cost by the number of items.

In a class of 30 students, 3/5 are girls. How many boys are in the class?

• a.12✓
• b.10
• c.15
• d.18

Three fifths of 30 is 18 girls. Subtracting 18 girls from 30 total students leaves 12 boys. The fraction of boys is the remaining two fifths of 30, which also equals 12.

A meal costs $40 before tax. If sales tax is 8%, what is the total amount paid?

• a.$42.00
• b.$43.20✓
• c.$44.80
• d.$48.00

Eight percent of $40 is $3.20 in tax. Adding the tax to the $40 meal gives a total of $43.20. Multiplying $40 by 1.08 gives the same total.

A tank holds 240 gallons and is being filled at 8 gallons per minute. How many minutes will it take to fill the empty tank?

• a.24 minutes
• b.32 minutes
• c.30 minutes✓
• d.40 minutes

Dividing the 240-gallon capacity by the fill rate of 8 gallons per minute gives 30 minutes. Time equals total amount divided by rate.

If 168 pencils are packed equally into boxes of 12, how many boxes are needed?

• a.12
• b.16
• c.18
• d.14✓

Dividing 168 pencils by 12 pencils per box gives exactly 14 boxes. Because 12 times 14 equals 168, there is no remainder and no extra box is required.

"Abundant" most nearly means:

• a.plentiful✓
• b.scarce
• c.hidden
• d.costly

Abundant describes something existing in large quantity or great supply. Plentiful is its closest synonym. Scarce is an antonym meaning in short supply.

"Cautious" most nearly means:

• a.reckless
• b.careful✓
• c.cheerful
• d.curious

Cautious means acting with care to avoid danger or mistakes. Careful is the nearest match. Reckless is the opposite, meaning careless.

"Vacant" most nearly means:

• a.crowded
• b.locked
• c.empty✓
• d.dirty

Vacant means not occupied or containing nothing. Empty is the closest synonym. A vacant lot or apartment has no one in it.

"Fatigue" most nearly means:

• a.hunger
• b.anger
• c.strength
• d.tiredness✓

Fatigue is a state of extreme weariness or exhaustion, usually from exertion. Tiredness is its nearest meaning. It is the opposite of feeling energetic.

"Rigid" most nearly means:

• a.stiff✓
• b.flexible
• c.smooth
• d.warm

Rigid means stiff and unable to bend easily. Stiff is the closest synonym. Flexible is the antonym, describing something that bends readily.

"Conceal" most nearly means:

• a.reveal
• b.hide✓
• c.gather
• d.clean

To conceal something is to keep it out of sight or secret. Hide is its nearest synonym. Reveal is the opposite, meaning to show.

"Ample" most nearly means:

• a.tiny
• b.broken
• c.sufficient✓
• d.rapid

Ample means more than enough or fully adequate in amount. Sufficient captures this meaning of an adequate supply. It is the opposite of insufficient.

"Diminish" most nearly means:

• a.expand
• b.repair
• c.brighten
• d.decrease✓

To diminish is to make or become smaller or less. Decrease is the closest synonym. Expand, meaning to grow larger, is its antonym.

"Novice" most nearly means:

• a.beginner✓
• b.expert
• c.leader
• d.traitor

A novice is a person new to a field or activity. Beginner is the nearest match. An expert, being highly skilled, is the opposite.

"Verify" most nearly means:

• a.deny
• b.confirm✓
• c.forget
• d.delay

To verify is to check or prove that something is true or accurate. Confirm is the closest synonym. Deny is an antonym meaning to reject as untrue.

"Hostile" most nearly means:

• a.welcoming
• b.quiet
• c.unfriendly✓
• d.wealthy

Hostile describes an unfriendly or antagonistic attitude. Unfriendly is the nearest meaning. Welcoming is the opposite.

"Fragment" most nearly means:

• a.whole
• b.engine
• c.signal
• d.piece✓

A fragment is a small broken-off part of something larger. Piece is the closest synonym. It contrasts with a whole or complete object.

"Prohibit" most nearly means:

• a.forbid✓
• b.allow
• c.praise
• d.measure

To prohibit something is to formally forbid it by rule or law. Forbid is the nearest synonym. Allow is the antonym, meaning to permit.

"Sturdy" most nearly means:

• a.fragile
• b.strong✓
• c.gentle
• d.distant

Sturdy means solidly built and strong. Strong is the closest match. Fragile, meaning easily broken, is its opposite.

"Vivid" most nearly means:

• a.dull
• b.silent
• c.bright✓
• d.heavy

Vivid describes something bright, intense, or strikingly clear. Bright is the nearest synonym. Dull is the antonym, meaning lacking brightness.

"Assemble" most nearly means:

• a.scatter
• b.ignore
• c.sell
• d.gather✓

To assemble is to bring or come together into a group or whole. Gather is the closest synonym. Scatter is the opposite, meaning to spread apart.

The human body loses water constantly through breathing, sweating, and digestion. To stay healthy, this lost water must be replaced by drinking fluids and eating foods that contain water. According to the passage, why must people drink fluids?

• a.To replace water the body loses✓
• b.To gain more energy
• c.To improve eyesight
• d.To build stronger muscles

The passage states the body constantly loses water and that this loss must be replaced. The correct choice restates that idea directly. The other options are not mentioned in the passage.

Recycling reduces the amount of waste sent to landfills. It also saves energy, because making products from recycled materials often uses less power than making them from raw materials. One benefit of recycling mentioned in the passage is that it:

• a.creates more landfills
• b.saves energy✓
• c.raises product prices
• d.uses more raw materials

The passage says recycling saves energy since recycled materials often require less power. That matches the correct choice. The remaining options contradict the passage.

A good study routine includes setting a regular time and place. Studying in the same spot each day helps the brain associate that location with focus, making it easier to concentrate. The passage suggests that studying in the same place each day helps a person to:

• a.finish homework faster
• b.avoid taking notes
• c.concentrate more easily✓
• d.study fewer subjects

The passage explains that a consistent location helps the brain associate it with focus, making concentration easier. The correct answer restates this. The other choices are not supported.

Firefighters wear heavy protective suits made of flame-resistant material. These suits shield the wearer from intense heat, but they are also very hot and tiring to work in. According to the passage, one drawback of the protective suits is that they:

• a.catch fire easily
• b.are too thin
• c.cannot be cleaned
• d.are hot and tiring to wear✓

The passage notes that although the suits protect against heat, they are hot and tiring to work in. That is the drawback described. The other options are not stated.

Bees play a vital role in agriculture. As they move from flower to flower collecting nectar, they carry pollen between plants, allowing many crops to produce fruit. The passage indicates that bees help crops by:

• a.carrying pollen between plants✓
• b.eating harmful insects
• c.watering the soil
• d.keeping the ground warm

The passage states bees carry pollen from flower to flower, which allows crops to produce fruit. That matches the correct choice. The other answers are not mentioned.

Reading aloud to young children builds their vocabulary. Hearing new words in context helps children understand meanings and remember the words later. According to the passage, hearing words in context helps children to:

• a.read silently
• b.understand and remember words✓
• c.write neatly
• d.speak more quietly

The passage says that hearing new words in context helps children grasp meanings and recall the words later. The correct option restates this. The others are not supported.

Regular exercise strengthens the heart. A stronger heart pumps blood more efficiently, which can lower a person's resting heart rate over time. The passage states that a stronger heart:

• a.beats faster at rest
• b.requires more oxygen
• c.pumps blood more efficiently✓
• d.shrinks in size

The passage explains that a stronger heart pumps blood more efficiently and can lower the resting heart rate. That matches the correct choice, while the others contradict the passage.

Many plants close their leaves or flowers at night. This response helps protect the plant from cold temperatures and reduces water loss during dark hours. According to the passage, closing at night helps plants by:

• a.attracting more insects
• b.producing more seeds
• c.growing taller quickly
• d.reducing water loss✓

The passage says that closing at night protects plants from cold and reduces water loss. The correct answer reflects this. The remaining choices are not mentioned.

A budget is a plan for spending money. By listing income and expenses, a budget helps a person avoid spending more than they earn. The main purpose of a budget, according to the passage, is to:

• a.plan spending and avoid overspending✓
• b.increase a person's income
• c.eliminate all expenses
• d.borrow more money

The passage defines a budget as a spending plan that lists income and expenses to prevent overspending. The correct choice captures this purpose. The others are not stated.

Sea turtles travel thousands of miles across the ocean but often return to the same beach where they hatched to lay their eggs. Scientists believe they use the Earth's magnetic field to navigate. According to the passage, sea turtles are believed to navigate using:

• a.the position of the moon
• b.the Earth's magnetic field✓
• c.ocean water temperature
• d.the sound of waves

The passage states that scientists believe sea turtles use the Earth's magnetic field to find their way. That matches the correct choice. The other options are not mentioned.

Getting enough sleep improves memory. During deep sleep, the brain organizes and stores information learned during the day, making it easier to recall later. The passage explains that during deep sleep the brain:

• a.stops all activity
• b.forgets the day's events
• c.organizes and stores information✓
• d.grows new bones

The passage says the brain organizes and stores the day's information during deep sleep, aiding recall. The correct answer restates this. The other choices are unsupported.

Traffic roundabouts can reduce accidents at intersections. Because vehicles move in the same direction around a circle, dangerous head-on and right-angle collisions are far less likely. According to the passage, roundabouts reduce accidents because vehicles:

• a.travel much faster
• b.stop more often
• c.use fewer lanes
• d.move in the same direction✓

The passage explains that roundabouts keep vehicles moving in the same direction, reducing head-on and right-angle crashes. The correct choice restates this reason. The others are not stated.

Salt has long been used to preserve food. It draws moisture out of meat and fish, creating conditions in which the bacteria that cause spoilage cannot easily grow. The passage indicates that salt preserves food by:

• a.drawing out moisture✓
• b.adding vitamins
• c.raising the temperature
• d.adding color

The passage says salt draws moisture out of food, making it hard for spoilage bacteria to grow. That matches the correct answer. The other options are not mentioned.

Volunteering benefits both the community and the volunteer. Besides helping others, volunteers often gain new skills and build friendships that improve their own lives. According to the passage, one way volunteering benefits the volunteer is by:

• a.increasing their salary
• b.helping them gain new skills✓
• c.reducing their taxes
• d.giving them free housing

The passage states that volunteers often gain new skills and build friendships. The correct choice reflects a benefit to the volunteer. The other options are not supported by the text.

If 3x + 7 = 22, what is the value of x?

• a.3
• b.7
• c.5✓
• d.9

Subtracting 7 from both sides gives 3x equals 15. Dividing both sides by 3 gives x equals 5. You can check by substituting 5 back into the equation.

What is the value of 4 squared plus 3 cubed?

• a.25
• b.37
• c.49
• d.43✓

Four squared is 16 and three cubed is 27. Adding 16 and 27 gives 43. Exponents are evaluated before addition.

The area of a triangle with base 10 and height 6 is:

• a.30✓
• b.16
• c.60
• d.45

The area of a triangle equals one half times base times height. That is 0.5 times 10 times 6, which equals 30 square units. Forgetting the one-half factor gives the incorrect value 60.

What is the value of x if x/4 = 9?

• a.13
• b.36✓
• c.18
• d.45

To isolate x, multiply both sides of the equation by 4. That gives x equals 9 times 4, or 36. Dividing 36 by 4 returns 9, which confirms the answer.

Simplify: 2(3 + 4) - 5.

• a.3
• b.7
• c.9✓
• d.12

Following order of operations, first add inside the parentheses to get 7. Multiply by 2 to get 14, then subtract 5 to reach 9.

A circle has a radius of 5. What is its circumference? (Use pi is about 3.14.)

• a.15.7
• b.25.0
• c.78.5
• d.31.4✓

Circumference equals 2 times pi times the radius. That is 2 times 3.14 times 5, which equals 31.4. The value 78.5 is the area, not the circumference.

What is the value of the expression 5! (5 factorial)?

• a.120✓
• b.25
• c.60
• d.720

A factorial multiplies all whole numbers from the number down to 1. So 5 factorial is 5 times 4 times 3 times 2 times 1, which equals 120.

Solve for y: 2y - 6 = 10.

• a.2
• b.8✓
• c.5
• d.16

Adding 6 to both sides gives 2y equals 16. Dividing both sides by 2 gives y equals 8. Substituting 8 back confirms the solution.

What is the square root of 144?

• a.11
• b.14
• c.12✓
• d.72

The square root of a number is the value that, multiplied by itself, gives that number. Since 12 times 12 equals 144, the square root of 144 is 12.

The sum of the interior angles of a triangle is:

• a.90 degrees
• b.270 degrees
• c.360 degrees
• d.180 degrees✓

The interior angles of any triangle always add up to 180 degrees. This is a fundamental rule of Euclidean geometry. A quadrilateral, by contrast, totals 360 degrees.

If a = 3 and b = -2, what is the value of a squared minus b?

• a.11✓
• b.7
• c.5
• d.-11

First, a squared is 3 times 3, which equals 9. Subtracting b, which is negative 2, means adding 2, giving 9 plus 2, or 11.

What is 3/4 written as a decimal?

• a.0.34
• b.0.75✓
• c.0.43
• d.1.33

Dividing the numerator 3 by the denominator 4 gives 0.75. Fractions are converted to decimals by dividing the top number by the bottom number.

A rectangle has a length of 8 and a perimeter of 26. What is its width?

• a.4
• b.6
• c.5✓
• d.9

The perimeter equals twice the length plus twice the width. So 26 minus 2 times 8, which is 16, leaves 10 for the two widths. Dividing 10 by 2 gives a width of 5.

Simplify the expression 3x + 2x - x.

• a.5x
• b.6x
• c.2x
• d.4x✓

Combining like terms, 3x plus 2x equals 5x, and subtracting x leaves 4x. Only the coefficients are added and subtracted since all terms share the variable x.

What is the value of 6 divided by 0.5?

• a.12✓
• b.3
• c.6
• d.0.083

Dividing by 0.5 is the same as multiplying by 2. So 6 divided by 0.5 equals 12. Dividing by a number less than 1 produces a result larger than the original.

A cube has edges of length 3. What is its volume?

• a.9
• b.27✓
• c.18
• d.81

The volume of a cube equals the edge length raised to the third power. Three cubed is 3 times 3 times 3, which equals 27 cubic units.

Which part of the plant cell carries out photosynthesis?

• a.Nucleus
• b.Mitochondrion
• c.Chloroplast✓
• d.Ribosome

Chloroplasts contain chlorophyll, the green pigment that captures light energy to make sugar during photosynthesis. The nucleus stores genetic material, while mitochondria release energy from food.

What is the chemical symbol for water?

• a.CO2
• b.O2
• c.NaCl
• d.H2O✓

Water is made of two hydrogen atoms bonded to one oxygen atom, giving the formula H2O. CO2 is carbon dioxide and NaCl is table salt.

Which gas do humans need to breathe in to survive?

• a.Oxygen✓
• b.Carbon dioxide
• c.Nitrogen
• d.Helium

The human respiratory system takes in oxygen, which cells use to release energy from food. Carbon dioxide is the waste gas that people breathe out.

The force that pulls objects toward the center of the Earth is called:

• a.Friction
• b.Gravity✓
• c.Magnetism
• d.Inertia

Gravity is the attractive force that pulls objects toward the Earth's center, giving them weight. Friction opposes motion between surfaces, and magnetism acts between magnetic materials.

Which planet is closest to the Sun?

• a.Venus
• b.Earth
• c.Mercury✓
• d.Mars

Mercury is the innermost planet, orbiting nearest to the Sun. Venus is second, Earth third, and Mars fourth.

What is the basic unit of heredity that carries traits from parents to offspring?

• a.Cell
• b.Tissue
• c.Organ
• d.Gene✓

A gene is a segment of DNA that carries the instructions for inherited traits. Cells, tissues, and organs are structural levels of the body, not units of heredity.

At what temperature does pure water freeze at sea level, in degrees Celsius?

• a.0 degrees✓
• b.32 degrees
• c.100 degrees
• d.-10 degrees

Pure water freezes at 0 degrees Celsius at standard sea-level pressure. That same point is 32 degrees on the Fahrenheit scale, while water boils at 100 degrees Celsius.

Which blood cells help fight infection in the body?

• a.Red blood cells
• b.White blood cells✓
• c.Platelets
• d.Plasma proteins

White blood cells are part of the immune system and defend the body against germs and infection. Red blood cells carry oxygen, and platelets help blood clot.

The process by which liquid water turns into water vapor is called:

• a.Condensation
• b.Precipitation
• c.Evaporation✓
• d.Freezing

Evaporation is the change of a liquid into a gas as molecules gain enough energy to escape the surface. Condensation is the reverse, when vapor turns back into liquid.

Which of these is an example of a chemical change?

• a.Ice melting
• b.Water boiling
• c.Tearing paper
• d.Iron rusting✓

Rusting forms a new substance, iron oxide, so it is a chemical change. Melting, boiling, and tearing are physical changes that do not create new substances.

The Richter scale is used to measure the strength of:

• a.Earthquakes✓
• b.Hurricanes
• c.Tornadoes
• d.Floods

The Richter scale measures the magnitude, or energy released, of earthquakes. Hurricanes and tornadoes are rated on different scales based on wind speed.

Which organ system is responsible for pumping blood throughout the body?

• a.Digestive system
• b.Circulatory system✓
• c.Nervous system
• d.Respiratory system

The circulatory system, centered on the heart and blood vessels, pumps blood to deliver oxygen and nutrients. The respiratory system handles breathing, and the digestive system processes food.

What type of energy is stored in a stretched rubber band?

• a.Kinetic energy
• b.Thermal energy
• c.Potential energy✓
• d.Sound energy

A stretched rubber band stores potential energy because of its position or state. When released, that stored energy converts into kinetic energy, the energy of motion.

Which part of the atom carries a negative electric charge?

• a.Proton
• b.Neutron
• c.Nucleus
• d.Electron✓

Electrons carry a negative charge and orbit the atom's nucleus. Protons carry a positive charge and neutrons have no charge, both residing in the nucleus.

Photosynthesis produces oxygen and which sugar?

• a.Glucose✓
• b.Sucrose
• c.Lactose
• d.Fructose

During photosynthesis, plants use carbon dioxide and water to make glucose and release oxygen. Glucose is the simple sugar plants use for energy and growth.

The layer of gases surrounding the Earth is called the:

• a.Lithosphere
• b.Atmosphere✓
• c.Hydrosphere
• d.Biosphere

The atmosphere is the envelope of gases held around Earth by gravity. The lithosphere is the solid crust, and the hydrosphere includes the planet's water.

According to Ohm's law, voltage equals current multiplied by:

• a.power
• b.capacitance
• c.resistance✓
• d.frequency

Ohm's law states that voltage equals current times resistance, written as V equals I times R. This relationship links the three basic quantities in a circuit.

The unit used to measure electrical resistance is the:

• a.volt
• b.ampere
• c.watt
• d.ohm✓

Resistance is measured in ohms, symbolized by the Greek letter omega. The volt measures voltage, the ampere measures current, and the watt measures power.

A device that stores electrical charge is a:

• a.capacitor✓
• b.resistor
• c.inductor
• d.transformer

A capacitor stores electrical energy in an electric field between two plates. A resistor limits current, while an inductor stores energy in a magnetic field.

In a circuit, current is measured in:

• a.ohms
• b.amperes✓
• c.volts
• d.farads

Electric current, the flow of charge, is measured in amperes, often shortened to amps. Ohms measure resistance, volts measure voltage, and farads measure capacitance.

What is the total resistance of two 10-ohm resistors connected in series?

• a.5 ohms
• b.10 ohms
• c.20 ohms✓
• d.100 ohms

In a series circuit, resistances add together directly. Ten ohms plus ten ohms equals 20 ohms. In parallel, the total would instead be lower than either resistor.

Electrical power in watts is calculated by multiplying voltage by:

• a.resistance
• b.time
• c.capacitance
• d.current✓

Power equals voltage times current, written as P equals V times I. This gives the rate at which electrical energy is used, measured in watts.

A component that allows current to flow in only one direction is a:

• a.diode✓
• b.resistor
• c.capacitor
• d.switch

A diode conducts current in one direction and blocks it in the other, acting like a one-way valve. This property makes diodes useful for converting AC to DC.

The abbreviation AC stands for:

• a.automatic circuit
• b.alternating current✓
• c.ampere current
• d.active charge

AC stands for alternating current, in which the direction of electron flow reverses periodically. DC, or direct current, flows steadily in one direction.

Which material is the best conductor of electricity?

• a.Rubber
• b.Glass
• c.Copper✓
• d.Wood

Copper is an excellent conductor and is widely used in electrical wiring. Rubber, glass, and wood are insulators that resist the flow of current.

A transformer is used to change the level of:

• a.resistance
• b.frequency
• c.current direction
• d.voltage✓

A transformer increases or decreases AC voltage using two coils of wire. Stepping voltage up or down helps electricity travel efficiently and power different devices.

If voltage is 12 volts and resistance is 4 ohms, what is the current?

• a.3 amperes✓
• b.2 amperes
• c.4 amperes
• d.48 amperes

Using Ohm's law, current equals voltage divided by resistance. That is 12 volts divided by 4 ohms, which equals 3 amperes.

A material that strongly resists the flow of electric current is called a(n):

• a.conductor
• b.insulator✓
• c.semiconductor
• d.battery

An insulator resists the flow of electricity and is used to protect and separate conductors. Rubber and plastic are common insulators used to coat wires.

The component that provides a source of stored electrical energy in a portable device is the:

• a.fuse
• b.switch
• c.battery✓
• d.antenna

A battery stores chemical energy and converts it to electrical energy to power a device. A fuse protects the circuit, and a switch simply opens or closes it.

A fuse protects a circuit by:

• a.increasing the voltage
• b.storing extra charge
• c.reversing the current
• d.breaking the circuit when current is too high✓

A fuse contains a thin wire that melts and breaks the circuit when current exceeds a safe level. This prevents overheating and damage to the rest of the circuit.

Which simple machine is a doorknob an example of?

• a.Wheel and axle✓
• b.Pulley
• c.Wedge
• d.Inclined plane

A doorknob turns a shaft, so the large knob and thin spindle form a wheel and axle. Turning the larger wheel produces a stronger turning force on the smaller axle.

A lever is used mainly to:

• a.store electricity
• b.increase force✓
• c.reduce weight
• d.produce heat

A lever multiplies the force applied to it, making it easier to move a load. Placing the fulcrum closer to the load increases this mechanical advantage.

If two people push on a box from opposite sides with equal force, the box will:

• a.move toward the stronger side
• b.spin in place
• c.stay still✓
• d.speed up

Equal and opposite forces cancel out, producing a net force of zero. With no net force, the box remains at rest, an example of balanced forces.

A pulley system is used to:

• a.create electricity
• b.reduce friction to zero
• c.increase temperature
• d.change the direction of a force✓

A single fixed pulley lets you pull down to lift a load up, changing the direction of the applied force. Adding more pulleys can also reduce the effort needed.

Which of these is an example of an inclined plane?

• a.A ramp✓
• b.A wheelbarrow
• c.A seesaw
• d.A ceiling fan

A ramp is a flat surface set at an angle, which is the definition of an inclined plane. It makes raising a load easier by spreading the effort over a longer distance.

The force that opposes the motion of two surfaces sliding against each other is:

• a.gravity
• b.friction✓
• c.tension
• d.buoyancy

Friction acts between contacting surfaces and resists their relative sliding motion. Rougher surfaces generally produce more friction than smooth ones.

In a class-one lever, the fulcrum is located:

• a.at the load end only
• b.at the effort end only
• c.between the effort and the load✓
• d.outside the lever

A class-one lever, such as a seesaw, has its fulcrum between the effort and the load. A crowbar prying a nail is another common example.

Two gears mesh together. If the driving gear turns clockwise, the driven gear will turn:

• a.clockwise
• b.in both directions
• c.not at all
• d.counterclockwise✓

When two gears mesh directly, they turn in opposite directions. So if the driving gear turns clockwise, the meshed driven gear turns counterclockwise.

A smaller gear driving a larger gear will cause the larger gear to turn:

• a.more slowly✓
• b.faster
• c.at the same speed
• d.backward only

A small gear driving a large gear reduces speed but increases turning force, or torque. The larger gear turns more slowly because it has more teeth to move per revolution.

Which object has the most gravitational potential energy?

• a.A rock at the bottom of a hill
• b.A rock at the top of a hill✓
• c.A rock rolling on flat ground
• d.A rock resting in a valley

Gravitational potential energy increases with height. A rock at the top of a hill is highest, so it has the greatest stored energy ready to convert to motion.

Increasing the length of a lever's effort arm will:

• a.decrease the force output
• b.have no effect
• c.increase the mechanical advantage✓
• d.reduce the load

A longer effort arm gives more leverage, increasing the mechanical advantage. This lets a smaller effort force lift a larger load.

Air pressure is greatest at:

• a.the top of a mountain
• b.high in the atmosphere
• c.the edge of space
• d.sea level✓

Air pressure is highest at sea level because the full weight of the atmosphere presses down there. Pressure decreases with altitude as less air remains above.

A wedge is used to:

• a.split or separate objects✓
• b.lift objects with a rope
• c.store rotational energy
• d.reduce electrical current

A wedge is a moving inclined plane that concentrates force to split or separate materials. An axe head and a knife blade are common wedges.

When a compressed spring is released, the stored energy is converted mainly into:

• a.heat only
• b.motion✓
• c.electricity
• d.sound only

A compressed spring stores elastic potential energy. When released, that energy is converted mainly into kinetic energy, causing the spring or an attached object to move.

Which engine component converts the up-and-down motion of the pistons into rotating motion?

• a.Camshaft
• b.Spark plug
• c.Crankshaft✓
• d.Radiator

The crankshaft is connected to the pistons and turns their linear up-and-down motion into rotational motion that drives the wheels. The camshaft instead controls the valves.

What is the main purpose of engine oil?

• a.To cool the cabin
• b.To power the lights
• c.To inflate the tires
• d.To lubricate moving parts✓

Engine oil lubricates moving metal parts to reduce friction and wear. It also helps carry away heat and keep internal components clean.

A spark plug is used to:

• a.ignite the fuel-air mixture✓
• b.cool the engine
• c.filter the oil
• d.charge the battery

In a gasoline engine, the spark plug produces an electric spark that ignites the compressed fuel-air mixture in the cylinder. This controlled ignition powers the piston stroke.

Which tool is best for measuring the gap of a spark plug?

• a.Torque wrench
• b.Feeler gauge✓
• c.Pipe wrench
• d.Hacksaw

A feeler gauge has thin blades of known thickness used to measure small gaps, such as a spark plug gap. A torque wrench instead measures tightening force.

The part of the car that keeps the engine from overheating by circulating coolant is the:

• a.alternator
• b.muffler
• c.radiator✓
• d.distributor

The radiator transfers heat from the circulating coolant to the outside air, keeping the engine at a safe temperature. The alternator, by contrast, generates electricity.

A Phillips screwdriver is designed to fit a screw head shaped like a:

• a.straight slot
• b.square
• c.hexagon
• d.cross✓

A Phillips screwdriver has a cross-shaped, or X-shaped, tip that matches a screw head with a cross-shaped recess. A flat-blade screwdriver instead fits a single straight slot.

Which part of a car stores electrical energy to start the engine?

• a.Battery✓
• b.Muffler
• c.Carburetor
• d.Fuel pump

The battery supplies the electrical current needed to power the starter motor and start the engine. Once running, the alternator recharges the battery.

The device that reduces engine exhaust noise is the:

• a.radiator
• b.muffler✓
• c.alternator
• d.clutch

The muffler is part of the exhaust system and dampens the loud noise created by the engine's exhaust gases. It does not affect engine cooling or charging.

A torque wrench is used to:

• a.cut metal pipe
• b.measure voltage
• c.tighten bolts to a specific tightness✓
• d.sand wood surfaces

A torque wrench applies a precise, measured amount of turning force to a bolt or nut. This prevents fasteners from being too loose or over-tightened and damaged.

Which type of saw is designed for cutting metal?

• a.Crosscut saw
• b.Coping saw
• c.Chainsaw
• d.Hacksaw✓

A hacksaw has a fine-toothed blade held under tension in a frame and is made for cutting metal and plastic. A crosscut saw and chainsaw are intended for wood.

The system that allows a car to slow down and stop is the:

• a.braking system✓
• b.cooling system
• c.fuel system
• d.exhaust system

The braking system uses friction, typically pads pressing on discs or rotors, to slow the wheels and stop the vehicle. The fuel and exhaust systems handle power, not stopping.

Which tool would you use to drive a nail into wood?

• a.Wrench
• b.Hammer✓
• c.Pliers
• d.Level

A hammer delivers a strong impact to drive nails into wood. Wrenches turn bolts, pliers grip objects, and a level checks whether a surface is horizontal.

In a four-stroke engine, which stroke immediately follows the compression stroke?

• a.Intake stroke
• b.Exhaust stroke
• c.Power stroke✓
• d.Cooling stroke

The four-stroke cycle runs intake, compression, power, then exhaust. After the fuel-air mixture is compressed, the spark plug fires and the power stroke pushes the piston down.

The purpose of a vehicle's transmission is to:

• a.cool the engine oil
• b.clean the exhaust gases
• c.store fuel
• d.transfer engine power to the wheels✓

The transmission uses gears to transfer the engine's power to the wheels while matching engine speed to driving conditions. Lower gears provide more force, higher gears more speed.