WorksheetsUnit Test- class 12 (physics)
Total questions: 20
Worksheet time: 24mins
Which one of the following represents correct units for electric field strength?
T
N/C
J/C
a. N • m 2 • C-2
The flow of charge per unit time defines
power
current
voltage
resistance
The diagram shows two positive charges of magnitude Q and 2Q.
Which vector best represents the direction of the electric field at point P, which is equidistant from both charges?
A 6.0 x 10 –6 C charge is located 4.0 m from a –3.0 x 10 –6 C charge as shown in fig.
What is the electric potential at P, halfway between the charges?
-4.1 x 10 –2 V
6.8 x 10 3 V
1.35 x 10 4 V
4.1 x 10 4 V
The diagram shows the electric field near two point charges L and R.
charge L - Positive and charge R - Positive
charge L - Positive and charge R - Negative
charge L - Negative and charge R - Positive
charge L - Negative and charge R - Negative
The electric field 2.0 m from a point charge has a magnitude of 8. 0 x 10 4 N/C. What is the strength of the electric field at a distance of 4.0 m?
2.0 x 104 N/C
4.0 x 104 N/C
1.6 x 10 5 N/C
3.2 x 10 5 N/C
When a charge is accelerated through a potential difference of 500 V, its kinetic energy increases from 2.0 x 10 -5 J to 6. 0 x 10 -5 J. What is the magnitude of the charge?
4.0 x 10 -8 C
8.0 x 10 -8 C
1. 2 x 10 -7 C
1. 6 x 10 -7 C
A negative charge in an electric field experiences a force accelerating it due south. What is the direction of the electric field?
East
West
North
South
A (- 2.3 x 10 -6) C charge exerts a repulsive force of magnitude 0.35 N on an unknown charge 0.20 m away. What are the magnitude and polarity of the unknown charge?
MAGNITUDE- 6.8 x 10 –7 C and Polarity - Negative
MAGNITUDE- 6.8 x 10 –7 C and Polarity - Positive
MAGNITUDE- 1.2 x 10 –6 C and Polarity - Negative
MAGNITUDE- 1.2 x 10 –6 C and Polarity - Positive
Two point charges, 2.5 x 10 -6 C and -5.0 x 10 -6 C , are placed 3.0 m apart as shown in fig.
What is the magnitude of the electric field at point P, midway between the two charges?
1.0 x 104 N /C
2.0 x 104 N/C
0 N/C
3.0 x 104 N/C
A 4.0 x 10 -9 C charge is initially located 3.0 m from a stationary 6. 0 x 10 -8 C charge. How much work is required to move the 4.0 x 10 -9 C charge to a point 0.50 m from the stationary charge?
6.0 x 10 -7 J
8.6 x 10 -7 J
3.6 x 10 -6 J
4.3 x 10 -6 J
Two parallel plates 4.0 x 10-2 m apart have a potential difference of 1 000 V. An electron is released from the negative plate at the same instant that a proton is released from the positive plate. Which of the following best compares their speed and kinetic energy as they strike the opposite plate?
Speed: Same, Kinetic Energy: Same
Speed: Same, Kinetic Energy: Different
Speed: Different, Kinetic Energy: Same
Speed: Different, Kinetic Energy: Different
The diagram shows a positive point charge Q.
Which of the following describes the magnitude and direction of the electric field at points r and s?
Same and away from Q
Same and towards Q
Different and away from Q
Different and towards Q
Two charges of equal magnitudes kept at a distance r exert a force F on each other. If the charges are halved and distance between them is doubled, then the new force acting on each charge is
F/8
F/4
4F
F/16
Three 15μF capacitors connected in series. The equivalent capacitance is
3μF
5μF
45μF
10μF
Capacity of capacitor in air is Co = 50 pF and the same in water is Cm = 105 pF, then the dielectric constant K is
4.1
2.1
3.2
2.3
If 5 J of work is needed to shift 10C of charge from one place to another. The potential difference between the places should be
0.5 V
0.7 V
1.5 V
5 V
If the capacitance of a parallel plate capacitor is 100µ F and the potential difference is 70µ F, the quantity of charge stored on each plate would be
70 mC each
7 mC each
700 mC each
0.7 mC each
The capacitance of the capacitor is independent of
The charges present on the plate
The distance of separation between the plates
The shape of the plates
The size of the plates
What does an electric dipole experience when it is kept in the non-uniform electric field?
Only a force
Only torque
Force and torque both
Neither force nor torque
