Optics CDS Questions

CDS Physics

Optics MCQ Questions


1.

What is the speed of light in a vacuum approximately?

A.

2 x 108 m/s

B.

3 x 108 m/s

C.

4 x 108 m/s

D.

5 x 108 m/s

😑 View Answer Rough Work Error
ANSWER :

B. 3 x 108 m/s

2.
The refractive index is defined as the ratio of the speed of light in vacuum to the speed of light in _____.
A.
a denser medium
B.
a rarer medium
C.
any medium
D.
a transparent medium
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ANSWER :
C. any medium
3.
The unit of focal length in SI units is:
A.
Centimeter
B.
Millimeter
C.
Meter
D.
Kilometer
😑 View Answer Rough Work Error
ANSWER :
C. Meter
4.

Fill in the blank: A convex lens produces a ___________ when the object is placed at its focal point.

A.

Real and inverted

B.

Virtual and upright

C.

Magnified

D.

Real image at infinity 

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ANSWER :

D. Real image at infinity 

5.
What principle is used in optical fibers?
A.
Total internal reflection
B.
Refraction
C.
Diffraction
D.
Dispersion
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ANSWER :
A. Total internal reflection
6.

The lens maker's formula is:

A.

1/f = (n-1)(1/R1 - 1/R2)

B.

1/f = (n+1)(1/R1 - 1/R2)

C.

f = R1 - R2

D.

f = n + 1/R

😑 View Answer Rough Work Error
ANSWER :

A. 1/f = (n-1)(1/R1 - 1/R2)