Light & Optics MCQs with Answers

An equilateral prism and air have a critical angle of 45°. If the incoming ray is perpendicular to the refracting surface, ?

• A.It is reflected from the second surface and emerges perpendicular from the third surface
• B.It passes straight through the prism without any deviation
• C.It undergoes total internal reflection at the first surface and returns back
• D.It refracts at the second surface and emerges parallel to the base

When an object is placed very close to a concave mirror its image will be?

• A.Virtual, erect and magnified
• B.Virtual, inverted and magnified
• C.Real, erect and diminished
• D.All of these

The energy of a photon is given by ?

• A.f/h
• B.h/f
• C.hf
• D.h + f

When a parallel beam of light rays strikes a smooth surface like mirrors, it will be reflected as parallel rays of light. This phenomenon is called?

• A.Diffuse Reflection
• B.Specular Reflection
• C.Refraction
• D.Dispersion

Maxwell derived mathematically that the speed of light is ?

• A.C = √μ₀ε₀
• B.C = μ₀ε₀
• C.C = 1/√μ₀ε₀
• D.C = μ₀/ε₀

LASER beam can be sharply focused because it is?

• A.Highly coherent
• B.Highly intense
• C.Monochromatic
• D.Highly directional

Past Paper MCQ

Which of the following statement is true?

• A.Sound travels faster in air than in steel
• B.Water boils at 100°C at any atmospheric pressure
• C.The speed of light in vacuum is approximately 3 × 10⁸ m/s
• D.All of these

Refraction occurs when a wave passes from one medium to another; what property of the wave changes in the new medium?

• A.Frequency
• B.Wavelength
• C.Velocity
• D.Amplitude

Photoelectric effect is shown by?

• A.Sound waves
• B.Light (electromagnetic radiation)
• C.Heat radiation
• D.Water waves

Colours in oily water on roads are due to which phenomenon?

• A.Diffraction
• B.Interference
• C.Polarization
• D.Scattering