JAMB Physics Past Questions & Answers - Page 174

866.

Calculate the refractive index of the material of the glass block shown in the diagram if YZ = 4cm

A.

0.40

B.

0.60

C.

1.50

D.

1.67

E.

2.50

Correct answer is D

n = \(\frac{\text{real depth}}{\text {apparent depth}}\)

\(\frac{10}{10^{-4}}\) = 1.6

867.

A ray of light is incident at an angle of 30o on a glass prism of refractive index 1.5. Calculate the angle through which the ray is minimally deviated in the prism. (The medium surrounding the prism is air)

A.

10.5o

B.

19.5o

C.

21.1o

D.

38.9o

E.

40.5o

Correct answer is A

n = \(\frac{sin i}{sin r}\)

sin r = \(\frac{30^o}{n}\)

sin r = \(\frac{0.5}{1.5}\)

sin r = 0.3333

r = 19.5o; Deviation 30 - 19.5 = 10.5o

868.

In the arrangement illustrated above, Y and B are yellow and blue transparent light filters respectively. The white object through the filters is

A.

blue

B.

red

C.

yellow

D.

green

E.

black

Correct answer is E

No explanation has been provided for this answer.