| Question (1):
Which of the following statements does not represent ohm's law?
|
| 1. |
current / potential difference = constant
|
| 2. |
potential difference / current = constant
|
| 3. |
potential difference = current x resistance
|
| 4. |
current = resistance x potential difference
|
|
| Ans: 4 |
|
| Question (2):
The unit of current is _____________.
|
| 1. |
ampere
|
| 2. |
watt
|
| 3. |
volt
|
| 4. |
coulomb
|
|
| Ans: 1 |
|
| Question (3):
The potential difference required to pass a current 0.2 A in a wire of resistance 20W is ____.
|
| 1. |
100 V
|
| 2. |
4 V
|
| 3. |
.01 V
|
| 4. |
40 V
|
|
| Ans: 2 |
|
| Question (4):
The resistance of an electric bulb drawing 1.2 A current at 6.0 V is ___________.
|
| 1. |
0 .5 W
|
| 2. |
5 W
|
| 3. |
0.2 W |
| 4. |
2 W |
|
| Ans: 2 |
|
| Question (5):
The unit of resistivity is ____________.
|
| 1. |
ohm
|
| 2. |
ohm / m
|
| 3. |
ohm-m
|
| 4. |
mho
|
|
| Ans: 3 |
|
| Question (6):
Two resistances of 100 W and zero ohm are connected in parallel. The overall resistance will be
|
| 1. |
100 W
|
| 2. |
50 W
|
| 3. |
25 W |
| 4. |
zero ohm |
|
| Ans: 1 |
|
| Question (7):
Three resistors 2 W , 3 W and 4 W are connected so that the equivalent resistance is 9 W . The resistors are connected _________.
|
| 1. |
all in series
|
| 2. |
all in parallel
|
| 3. |
2 W and 3 W in parallel and the combination in series with 4 W |
| 4. |
2 W and 3 W in series and the combination in parallel to 4 W |
|
| Ans: 1 |
|
Question (8):
In the figure,
|
| 1. |
6 W , 3 W and 9 W are in series
|
| 2. |
9 W and 6 W are in parallel and the combination is in series with 3 W
|
| 3. |
3 W , 6 W and W are in parallel
|
| 4. |
3 W , 6 W are in parallel and 9 W is in series
|
|
| Ans: 4 |
|
Question (9):
The resistance across AB is
|
|
|
| Ans: 2 |
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| Question (10):
When a current 'I' flows through a resistance 'R' for time 't' the electrical energy spent is given by ___________.
|
| 1. |
I R t
|
| 2. |
I2 R t
|
| 3. |
I R2 t
|
| 4. |
I 2 R / t
|
|
| Ans: 2 |
|
| Question (11):
Kilowatt - hour is the unit of ______________.
|
| 1. |
potential difference
|
| 2. |
electric power
|
| 3. |
electrical energy
|
| 4. |
charge
|
|
| Ans: 3 |
|
| Question (12):
When a fuse is rated 8 A, it means _____________.
|
| 1. |
it will not work if current is less than 8 A
|
| 2. |
it has a resistance of 8 W
|
| 3. |
it will work only if current is 8 A
|
| 4. |
it will melt if current exceeds 8 A
|
|
| Ans: 4 |
|
| Question (13):
The device used for measuring potential difference is known as _____________.
|
| 1. |
potentiometer
|
| 2. |
ammeter
|
| 3. |
galvanometer
|
| 4. |
voltmeter
|
|
| Ans: 4 |
|
| Question (14):
The work done in moving a unit positive charge across two points in an electric circuit is a measure of ___________.
|
| 1. |
current
|
| 2. |
potential difference
|
| 3. |
resistance
|
| 4. |
power
|
|
| Ans: 2 |
|
| Question (15):
The potential at a point is 20 V. The work done to bring a charge of 0.5 C from infinity to this point will be ________.
|
| 1. |
20 J
|
| 2. |
10 J
|
| 3. |
5 J
|
| 4. |
40 J
|
|
| Ans: 2 |
|
| Question (16):
Joule / Coulomb is same as ______________.
|
| 1. |
watt
|
| 2. |
volt
|
| 3. |
ampere
|
| 4. |
ohm
|
|
| Ans: 2 |
|
| Question (17):
The free electrons of a metal _____________.
|
| 1. |
do not collide with each other
|
| 2. |
are free to escape through the surface
|
| 3. |
are free to fall into the nuclei
|
| 4. |
are free to move anywhere in the metal
|
|
| Ans: 4 |
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| Question (18):
The path of a free electron in a metal is ___________.
|
| 1. |
parabolic
|
| 2. |
circular
|
| 3. |
a straight line
|
| 4. |
zig zag
|
|
| Ans: 4 |
|
| Question (19):
Heat produced in a current carrying wire in 5s is 60 J. The same current is passed through another wire of half the resistance. The heat produced in 5 s will be _____________.
|
| 1. |
60 J
|
| 2. |
30 J
|
| 3. |
15 J
|
| 4. |
120 J
|
|
| Ans: 2 |
|
| Question (20):
The current in a wire ______________. |
| 1. |
depends only on the potential difference applied
|
| 2. |
depends only on the resistance of the wire
|
| 3. |
depends on both resistance and potential difference |
| 4. |
does not depend on resistance and potential difference |
|
| Ans: 3 |
|
| Question (21):
When there is an electric current passing through a wire, the particles moving are _____________.
|
| 1. |
electrons
|
| 2. |
protons
|
| 3. |
atoms
|
| 4. |
ions
|
|
| Ans: 1 |
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| Question (22):
A positive charge released from rest __________.
|
| 1. |
moves towards the regions of lower potential
|
| 2. |
moves towards the regions of higher potential
|
| 3. |
moves towards the regions of equal potential
|
| 4. |
does not move
|
|
| Ans: 1 |
|
| Question (23):
Three equal resistances when combined in series are equivalent to 90 W . Their equivalent resistance when combined in parallel will be __________.
|
| 1. |
270 W
|
| 2. |
30 W
|
| 3. |
810 W |
| 4. |
10 W |
|
| Ans: 4 |
|
| Question (24):
An battery is used to ________________.
|
| 1. |
maintain a potential difference
|
| 2. |
measure electric current
|
| 3. |
measure electric potential
|
| 4. |
safeguard against short - circuit
|
|
| Ans: 1 |
|
| Question (25):
Ohm's law relates potential difference with ___________.
|
| 1. |
power
|
| 2. |
energy
|
| 3. |
current
|
| 4. |
time
|
|
| Ans: 3 |
|
| Question (26):
Which of the following is an ohmic resistor?
|
| 1. |
Diode
|
| 2. |
Germanium
|
| 3. |
Nichrome
|
| 4. |
Diamond
|
|
| Ans: 3 |
|
| Question (27):
The resistivity of a wire depends on ____.
|
| 1. |
length
|
| 2. |
material
|
| 3. |
area of cross- section
|
| 4. |
length, material and area of cross- section |
|
| Ans: 4 |
|
| Question (28):
For which of the following substances, resistance decreases with temperature?
|
| 1. |
Copper
|
| 2. |
Platinum
|
| 3. |
Mercury
|
| 4. |
Carbon
|
|
| Ans: 4 |
|
| Question (29):
Four cells each of e.m.f 'E' are joined in parallel to form a battery. The equivalent e.m.f of the battery will be _______.
|
| 1. |
4 E
|
| 2. |
E
|
| 3. |
E / 4
|
| 4. |
E = 0
|
|
| Ans: 2 |
|
| Question (30):
Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them are in the ratio _________.
|
| 1. |
1:2
|
| 2. |
2:1
|
| 3. |
4:1
|
| 4. |
1:1
|
|
| Ans: 2 |
|
