GRE Subject 2026 Practice Test Physics Optics Free Quiz 2

11. What does Young's double-slit experiment demonstrate?

A. Reflection B. Refraction C. Diffraction D. Interference

12. What is the bending of waves around obstacles?

A. Diffraction B. Reflection C. Refraction D. Interference

13. What is the diffraction grating equation?

A. d sin θ = mλ B. d cos θ = mλ C. d sin θ = mλ D. d tan θ = mλ

14. What is polarization?

A. Reflection B. Refraction C. Diffraction D. Polarization

15. What is Malus's Law?

A. I = I₀ cos² θ B. I = I₀ sin² θ C. I = I₀ cos θ D. I = I₀ sin θ

16. Which part of the eye focuses light?

A. Cornea B. Retina C. Pupil D. Lens

17. What type of lens corrects myopia?

A. Convex B. Concave C. Cylindrical D. Bifocal

18. What type of lens corrects hyperopia?

A. Convex B. Concave C. Cylindrical D. Bifocal

19. What is the speed of light in a vacuum?

A. 3.00 × 10⁶ m/s B. 3.00 × 10¹⁰ m/s C. 3.00 × 10⁸ m/s D. 3.00 × 10¹² m/s

20. What phenomenon forms a rainbow?

A. Dispersion B. Reflection C. Refraction D. Diffraction