WAEC Physics Past Questions & Answers - Page 299

1,491.

The diagram above shows an incident ray A, inclined at angle of 50o to the interface CB. The ray OB is found to lie along the surface. What is the refractive index of the medium X with respect to air?

A.

sin50o/sin40o

B.

sin40osin50o

C.

sin90o/sin50o

D.

sin40o/sin90o

E.

sin90o/sin40o

Correct answer is E

No explanation has been provided for this answer.

1,492.

A parallel beam of light is to be obtained from the headlamp ofa car. At which of the following positions should the source of light be placed from the pole of its spherical minor?

A.

At the focal point

B.

At the centre of curvature

C.

Beyond the centre of curvature

D.

Between the focal point and the pole

E.

Between the focal point and the center of curvature

Correct answer is A

No explanation has been provided for this answer.

1,493.

Where will the image of the object OB shown in the diagram above be located after reflection from the mirror?

A.

At F

B.

Beyond C

C.

Between O and P

D.

Between P and F

E.

Between F and C

Correct answer is D

No explanation has been provided for this answer.

1,494.

A concave mirror of radius of curvature 20cm has a pin placed at 15cm from its pole. What will be the magnification of the image formed?

A.

4.00

B.

2.00

C.

1.33

D.

1.50

E.

0.25

Correct answer is B

1/U + 1/V = 1/f
f = r/2 = 10cm; 1/15 + 1/v = 1/10
v = 30 = m = v/u = 2