Waec Physics 1993 Past Questions and Answers

Question 36:

• WAEC 1993

In a series R - C circuit, the resistance of the resistor is 4 Ω and capacitive reactance is 3 Ω. Calculate the impedance of the circuit

A. 1Ω
B. 4Ω
C. 5Ω
D. 7Ω
E. 12Ω

Question 37:

• WAEC 1993

The vector diagram shown below represents the resistance R, the capacitive reactance X_c, the inductive reactance X_c and the impedance, Z in an R-L-C circuit. The current in the circuit will be maximum when

A. X_c = X_c
B. X_L = X_L
C. R = X_L
D. R =X

Question 38:

• WAEC 1993

In a purely resistive a.c. circuit, the current I = I_o sin wt and voltage, V = V_o sin wt. Calculate the instantaneous power dissipated in the circuit in time t.

A. I_o V_o
B. 2I_o V_osin wt
C. (I_o V_o)/2
D. I_o V_o sin²wt
E. I²_o V²_o

Question 39:

• WAEC 1993

A point charge of 1.0 x 10^-7 C experiences force of 0.01 N in a uniform electric field. Calculate the magnitude of the strength of the field

A. 10⁶ Vm^-1
B. 10⁵ Vm^-1
C. 10^-5 Vm^-1
D. 10² Vm^-1
E. 10⁹ Vm^-1

Question 40:

• WAEC 1993

The potential difference between two points A and B situated at a distance d apart is V. Which of the following expresses the magnitude of the electric field intensity between the two points assuming the field is uniform?

A. Vd
B. DV^-1
C. Vd^-1
D. V²d
E. D²V