Light & Optics MCQs with Answers

Why does the sun appear red at sunrise and sunset?

• A.Due to reflection of light
• B.Due to scattering of light
• C.Due to refraction of light
• D.Due to dispersion of light

A wavelength of 245 nm occurs in which portion of the electromagnetic spectrum?

• A.Visible light
• B.Ultraviolet
• C.Infrared
• D.X-rays

If red light is incident on sea water it appears _?

• A.Blue
• B.Green
• C.Black
• D.Red

If an object is placed at the principal focus of a convex lens, its image will be formed at ?

• A.At the centre of curvature
• B.At infinity
• C.At twice the focal length
• D.Between focus and optical centre

The Tyndall effect is used to distinguish between ?

• A.Acids and Bases
• B.Elements and Compounds
• C.Solutions and Colloids
• D.Metals and Non-metals

Focal length of astronomical telescope is?

• A.50 cm
• B.200 cm
• C.150 cm
• D.100 cm

In a reflecting telescope, a and is used.

• A.Convex lens; plane mirror
• B.Concave mirror; convex lens
• C.Convex mirror; concave lens
• D.Concave lens; plane mirror

Electron has a much shorter wavelength than visible light, and this allows electron microscopes to produce _ images.

• A.Higher-resolution
• B.Lower-resolution
• C.Colored
• D.Three-dimensional

What is the primary use of optical fibres?

• A.Electrical wiring
• B.Thermal insulation
• C.Telecommunications
• D.Structural reinforcement

Past Paper MCQ

What type of lens does a camera use to form an image that is real, inverted, and diminished?

• A.Concave lens
• B.Convex lens
• C.Plano-concave lens
• D.Cylindrical lens