Light & Optics MCQs with Answers

Which two primary colours are mixed to make purple?

• A.Red and green
• B.Red and yellow
• C.Blue and yellow
• D.Red and blue

Which series falls in the ultraviolet region?

• A.Balmer
• B.Paschen
• C.Lyman
• D.Brackett

The absorption of X-rays in a given material follows _?

• A.An exponential curve
• B.A linear curve
• C.A parabolic curve
• D.A sinusoidal curve

Television signals cannot be received ordinarily beyond a particular distance due to ?

• A.Curvature of earth
• B.Weak signal strength
• C.Atmospheric absorption
• D.Solar interference

The list that shows electromagnetic waves in order of an increasing wavelength is _?

• A.Gamma-rays, Microwaves, X-rays
• B.Microwaves, X-rays, Gamma-rays
• C.X-rays, Gamma-rays, Microwaves
• D.Gamma-rays, X-rays, Microwaves

What is correct for all transverse waves?

• A.They can all be polarized
• B.They require a medium to travel
• C.They are all electromagnetic in nature
• D.They all travel at the speed of light

The kinetic energy of an electron ejected from a metal surface exposed to monochromatic radiation depends on the _?

• A.Frequency of the light used
• B.Intensity of the light used
• C.Duration of exposure to light
• D.Temperature of the metal surface

What is the value of the Rydberg constant (R)?

• A.1.097×10⁹ m⁻¹
• B.1.097×10⁵ m⁻¹
• C.1.097×10³ m⁻¹
• D.1.097×10⁷ m⁻¹

When a certain metal surface is illuminated with light of frequency v, the stopping potential for photoelectric current is V₀. When the same surface is illuminated by light of frequency v/2, the stopping potential is V₀/4. The threshold frequency for photoelectric emission is ?

• A.v/6
• B.v/2
• C.v/4
• D.v/3

The mixture of yellow and green will make ?

• A.Blue
• B.Purple
• C.Orange
• D.Lime Color