Physics Past Questions and Answers

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

A 1Î©
B 4Ω
C 5Î©
D 7Î©
E 12Î©

Question 337:

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 338:

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 339:

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 340:

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