Physics 1991 Waec Past Questions and Answers

Question 26 :

• WAEC 1991

A ray of light is incident at an angle of 30^o 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. 10.5^o
B. 19.5^o
C. 21.1^o
D. 38.9^o
E. 40.5^o

Question 27 :

• WAEC 1991

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

Question 28 :

• WAEC 1991

An image which can be formed on a screen is said to be

A. Virtual
B. Blurred
C. Inverted
D. Erect
E. Real

Question 29 :

• WAEC 1991

Which of the following are true of plane-polarised right? i. Plane polarisation of light is the formation of hydrogen bubbles on the particle of light. ii. Plane components. iii. A plane polarised light vibrates in one plane. iv. Polarisation of light is characteristic of transverse vibration

A. I and ii only
B. I and iv only
C. Ii and iii only
D. I and ii only

Question 30 :

• WAEC 1991

At which of the following distances from the lens should a slide be placed on a slide projector if f is the focal length of the projector length?

A. Less than f
B. Greater than f but less than 3f
C. Equal to f
D. Equal to 2f
E. Greater than 2f