Free PTS Practice Questions

Question 1

A technician is selecting protective eyewear for a 1064 nm Nd:YAG laser. A colleague argues that because the beam is invisible, it poses less risk to the eye than a visible 532 nm beam of equal power. This reasoning is:

Accepted Answer

Incorrect, since 1064 nm reaches the retina but triggers no aversion response

Answer

Correct, since the retina responds only to wavelengths within the visible spectrum

Answer

Correct, since the lens and vitreous humor absorb wavelengths longer than 700 nm

Answer

Incorrect, since 1064 nm is absorbed at the cornea, causing severe surface injury

Question 2

A continuous-wave laser emits 300 mW at 633 nm. Its hazard classification is:

Accepted Answer

Class 3B, because output falls between 5 mW and 500 mW

Answer

Class 2, because the beam is visible and the blink reflex provides protection

Answer

Class 3R, because the power is below the 500 mW limit

Answer

Class 4, because any output above 100 mW is capable of igniting materials

Question 3

During alignment of a Class 4 laser, a technician defeats a safety interlock. Before proceeding, the MOST critical requirement is to:

Accepted Answer

Obtain Laser Safety Officer authorization and establish temporary controls

Answer

Post an illuminated warning sign at every entrance to the laser controlled area

Answer

Reduce the laser to its lowest usable output power before defeating the interlock

Answer

Confirm that all personnel present are wearing eyewear rated for the wavelength

Question 4

Which statement correctly distinguishes ANSI Z136.1 from 21 CFR 1040.10?

Accepted Answer

Z136.1 is a voluntary standard for safe use; 1040.10 is a mandatory manufacturing regulation

Answer

Z136.1 is a mandatory federal regulation for users; 1040.10 is voluntary industry guidance

Answer

Z136.1 sets requirements for Class 3B and Class 4 only; 1040.10 covers all remaining classes

Answer

Z136.1 is enforced during facility inspection; 1040.10 is enforced by the Laser Safety Officer

Question 5

Light travels from crown glass (n = 1.52) toward air. The critical angle, measured from the normal, is approximately:

Accepted Answer

41.1°

Answer

33.3°

Answer

48.9°

Answer

56.7°

Question 6

A beam of light passes from vacuum into fused silica. Which quantity remains unchanged?

Accepted Answer

Frequency

Answer

Propagation speed

Answer

Wavelength

Answer

Photon energy

Question 7

Unpolarized light passes through a polarizer, then through a second polarizer oriented at 60° to the first. The fraction of the ORIGINAL intensity transmitted is:

Accepted Answer

12.5%

Answer

50%

Answer

43.3%

Answer

25%

Question 8

An object is placed 30 cm from a converging lens of 10 cm focal length. The image formed is:

Accepted Answer

Real, inverted, and reduced

Answer

Real, inverted, and magnified

Answer

Virtual, upright, and reduced

Answer

Virtual, upright, and magnified

Question 9

A mirror is specified as 'HR > 99.8% @ 1064 nm, 45° AOI.' A technician installs it at normal incidence. The MOST likely result is:

Accepted Answer

Reduced reflectivity, because dielectric coatings are designed for a specific angle

Answer

Performance is unaffected, since reflectivity is a property of the coating material

Answer

Immediate coating damage caused by the increased power density at normal incidence

Answer

A measurable shift in the centre wavelength of the reflected beam

Question 10

A diffraction grating with 600 lines/mm is illuminated at normal incidence by a 633 nm HeNe laser. The first-order diffracted beam appears at approximately:

Accepted Answer

22.3°

Answer

11.0°

Answer

38.0°

Answer

45.6°

Free PTS Practice Questions

Domain 2: Principles of Optics: Nature of Light, Geometrical Optics, Wave Optics

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Domain 4: Safety

Question 7

Question 8

Question 9

Question 10

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