CSLB General Building (B) Trade Practice Test

Câu hỏi luyện tập mẫu

Một vài câu hỏi thực tế từ ngân hàng miễn phí này, kèm giải thích đầy đủ. Dùng công cụ luyện tập ở trên cho toàn bộ.

1. 1. Ophthalmic Optics

   What is the focal length of a +2.00 D lens?

   • a.10 cm
   • b.25 cm
   • c.50 cm
   • d.200 cm

   Đáp án: c

   Giải thích: Focal length in meters equals 1 divided by the lens power in diopters. 1 / 2.00 = 0.50 m, or 50 cm. A stronger plus lens would have a shorter focal length.

2. 2. Ophthalmic Optics

   If the distance Rx is -3.00 D and the add is +2.00 D, what is the total power in the reading portion?

   • a.-1.00 D
   • b.-5.00 D
   • c.+2.00 D
   • d.-3.00 D

   Đáp án: a

   Giải thích: The near power equals the distance sphere plus the add. -3.00 + 2.00 = -1.00 D in the reading zone.

3. 3. Ophthalmic Optics

   A prism deviates light in which direction?

   • a.Toward the base
   • b.There is no deviation
   • c.Toward the apex
   • d.Along the axis

   Đáp án: c

   Giải thích: Light passing through a prism bends toward the thick base, while the image seen through it displaces toward the thin apex. Prism power is measured in prism diopters.

4. 4. Prescription Analysis

   Transpose the Rx: +2.00 -1.00 x 090 into plus-cylinder form.

   • a.+1.00 +1.00 x 180
   • b.+3.00 -1.00 x 180
   • c.+2.00 +1.00 x 090
   • d.+1.00 -1.00 x 090

   Đáp án: a

   Giải thích: To transpose: add the sphere and cylinder for the new sphere (+2.00 + -1.00 = +1.00), change the cylinder sign (+1.00), and rotate the axis 90 degrees (090 becomes 180). Result: +1.00 +1.00 x 180.

5. 5. Prescription Analysis

   Compensated (effective) power differs from the prescribed power mainly due to what?

   • a.Frame color
   • b.Lens tint
   • c.Vertex distance and lens tilt
   • d.Bridge size

   Đáp án: c

   Giải thích: When a high-powered lens sits at a vertex distance or tilt different from where it was refracted, its effective power on the eye changes, so a compensated power is calculated to preserve the intended correction.

6. 6. Prescription Analysis

   Compensated power calculations are most critical when the fitted vertex distance differs from what?

   • a.The frame PD
   • b.The refracted vertex distance
   • c.The seg height
   • d.The base curve

   Đáp án: b

   Giải thích: The refraction is done at a specific vertex distance; when the dispensed frame sits at a different vertex distance, the effective power shifts, so compensation restores the intended power at the eye.

7. 7. Dispensing

   High-minus lenses can be made cosmetically thinner at the edge by doing what?

   • a.Increasing the base curve
   • b.Adding pantoscopic tilt
   • c.Using a higher-index material and edge treatments like a roll and polish
   • d.Choosing a larger frame

   Đáp án: c

   Giải thích: Higher-index materials reduce edge thickness for minus lenses, and a smaller frame plus proper decentration further reduces thickness. Rolling and polishing the edge improves the cosmetic appearance.

8. 8. Dispensing

   For a progressive lens, insufficient seg/fitting height (frame too shallow) causes what problem?

   • a.Distance blur
   • b.Too much add power
   • c.Excess prism
   • d.Not enough room for the reading zone, cutting off near vision

   Đáp án: d

   Giải thích: Progressive corridors need adequate vertical depth; if the frame's B measurement is too small, the reading portion at the bottom is cut off, leaving the wearer with inadequate near vision.

9. 9. Instruments & Regulatory

   Under FDA regulations, all dress eyewear lenses sold in the United States must be what?

   • a.Made of glass
   • b.Tinted
   • c.Impact resistant (capable of passing the drop-ball test)
   • d.Polarized

   Đáp án: c

   Giải thích: The FDA requires prescription and non-prescription dress lenses to be impact resistant, historically demonstrated by the drop-ball test, to protect wearers from lens shattering into the eye.

   Nguồn: FDA impact resistance

10. 10. Optical Math

    Using Prentice's rule, how much prism is induced when a +4.00 D lens is decentered 5 mm?

    • a.1.0 prism diopter
    • b.2.0 prism diopters
    • c.20 prism diopters
    • d.0.5 prism diopters

    Đáp án: b

    Giải thích: Prentice's rule: prism (prism diopters) = decentration (cm) x power (D). 5 mm = 0.5 cm; 0.5 x 4.00 = 2.0 prism diopters.