Waec Physics Past Questions For Year 1992
Question 21
The image of a pin formed by a diverging lens of focal length 10cm is 5cm from the lens. Calculate the distance of the pin from the lens
- A. -3.3cm
- B. 3.3cm
- C. 10.0cm
- D. 15.0cm
- E. 20.0cm
Question 22
In an experiment to measure1 the focal length f of a converging lens object distances u and corresponding image distance were measured and 1/u plotted against 1/v to obtain the graph illustrated. How would f be determined from this graph?
- A. f= the slope of the graph
- B. f= the intercept on the 1/u axis
- C. f =the intercept on the 1/v axis
- D. f = reciprocal of the slope
- E. f = reciprocal of the intercept on either axes
Question 23
Which of the following statements is not correct for a light ray passing through a rectangular glass block which is surrounded by air? It
- A. suffers a displacement at the point of emergence
- B. emerges parallel to the incident ray
- C. is partly reflected at the point of incidence
- D. is deviated at the point of emergence
- E. is reflected in the block
Question 24
Images formed by a convex mirror are always
- A. inverted, real and diminished
- B. inverted, virtual and diminished
- C. erect, virtual and diminished
- D. erect, real and magnified
- E. erect, virtual and magnified
Question 25
A ray of light strikes a plane mirror at an angle of incidence i. Determine in terms of i the angle of deviation of the ray after reflection from the mirror.
- A. i
- B. 2i
- C. 90o-i
- D. 90o+ i
- E. 180o - 2i
