Waec Physics 1997 Past Questions and Answers

Question 31:

• WAEC 1997

In a photocell, light energy is converted to

A. Electrical energy
B. Chemical energy
C. Heat energy
D. Mechanical energy
E. Kinetic energy

Question 32:

• WAEC 1997

Two identical waves traveling in the same direction are superimposed. What should be the phase difference between the waves for maximum destructive interference to occur?

A. 20°
B. 45°
C. 180°
D. 225°
E. 270°

Question 33:

• WAEC 1997

When a resistor of resistance R is connected across a cell, the terminal p.d of the cell is reduced to three quarters of its e.m.f. The internal resistance of the cell is expressed as

A. R/4
B. R/3
C. R/2
D. 3R/4
E. 3R

Question 34:

• WAEC 1997

A pipe open at both ends, produces a fundamental note. If the velocity of sound in air is V and L the length of the pipe, which of the following expresses the frequency of the note? Neglect end correction

A. 2V/L
B. V/2L
C. V/3L
D. V/4L
E. V/5L

Question 35:

• WAEC 1997

Which of the following statements is not correct?

A. The pitch of a note depends on the frequency of the vibrating source
B. The loudness of a note depends on its intensity
C. The velocity of sound in air does not depend on the intensity of the note producing it
D. The overtones present in a note determine its quality
E. Wind speed effects on the speed of sound in air