JAMB Physics Past Questions & Answers - Page 290

1,446.

The angle between the direction of the earth's magnetic field and the horizontal is called the

A.

angle of deviation

B.

magnetic declination

C.

magnetic meridian

D.

angle of dip

Correct answer is D

No explanation has been provided for this answer.

1,447.

Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?

A.

Gamma rays, ultraviolet rays, X- rays, infra - red rays

B.

Gamma rays, X-rays, ultraviolet rays, infra-red rays

C.

infra-red rays, ultraviolet rays, X-rays, gamma rays

D.

Gamma rays, ultraviolet rays, infra-red rays, X-rays

Correct answer is B

No explanation has been provided for this answer.

1,448.

If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?

A.

30o

B.

42o

C.

45o

D.

50o

Correct answer is A

sin c = \(\frac{1}{n}\) = \(\frac{1}{2}\)

c = sin-1\((\frac{1}{n})\)

= 30o

1,449.

The speed of light in air is 3 x 108ms-1. What is the speed in glass with a refractive index of 1.50?

A.

1.5 x 108ms-1

B.

3.0 x 108ms-1

C.

2.0 x 108ms-1

D.

6.0 x 108ms-1

Correct answer is C

1.5 = \(\frac{3 \times 10^8}{v}\)

v = 2.0 x 108ms-1

1,450.

Which of the following statements is CORRECT about a long-sighted boy who does not put on glasses?

A.

He cannot see distant objects clearly

B.

Rays of light from a close object are focused in front of his retina

C.

His eye ball is too long

D.

Parallel rays of light are focused behind his retina

Correct answer is D

No explanation has been provided for this answer.