1 |
Instead of moving the coil towards a magnet, the magnet is moved towards the coil with the same speed. The galvanometer shows current: |
Of same magnitude in the same direction
Of different magnitude in the same direction
Of same magnitude but in opposite direction
Of different magnitude in the opposite direction
None of these
|
2 |
When there is no relative motion between the magnet and coil, the galvanometer indicates: |
No current in circuit
An increasing current
A decreasing current
Either B or C
|
3 |
The magnitude of induced emf depends upon the: |
Rate of decrease of magnetic field
Rate of change of magnetic field
Rate of increase of magnetic flux
Constancy of magnetic field
None of these
|
4 |
Micheal Faraday and joseph Henry belong respectively to: |
USA and England
England and France
England and USA
USA and France
None of these
|
5 |
In magnet-coil experiment, emf can be produced by: |
Keeping the coil stationary and moving the magnet
Keeping the magnet stationary and moving the coil
Relative motion of the loop and magnet
Any one of above
All above
|
6 |
The induced current in the loop can be increased by: |
Using a strong magnetic field
Moving the loop faster
Replacing the loop by a coil of many turns
All of above
None of these
|
7 |
The induced current in a conductor depends upon: |
Resistance of the loop
Speed with which the conductor moves
Any of these
Both A and B
None of these
|
8 |
The phenomenon of generation of induced emf is called: |
Electrostatic induced
Magnetic induced
Electromagnetic induced
Electric induced
Both A and C
|
9 |
An
induced current can be produced by: |
<span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Constant magnetic field</span>
<span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Changing magnetic field</span>
<span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Varying magnetic field</span>
<span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Constant electric field</span>
<span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">None of these</span>
|
10 |
An induced current can be produced by: |
Constant magnetic field
Changing magnetic field
Varying magnetic field
Constant electric field
None of these
|
11 |
An emf is set up in a conductor when it: |
Is kept in a magnetic field
Is kept in an electric field
Moves across a magnetic field
Both A and B
None of these
|
12 |
The current produced by moving a loop of wire across a magnetic field is called: |
Direct current
Magnetic current
Alternating current
Induced current
None of these
|
13 |
Eddy current is produced when: |
A metal is kept in varying magnetic field
A metal is kept in steady magnetic field
A circular coil is placed in a steady magnetic field
A current is passed through a circular coil
|
14 |
Step up transformer has a transformation ratio of 3:2. What is the voltage in secondary, if voltage in primary is 30V: |
45 V
15 V
90 V
300 V
|
15 |
Which of the following quantities remain constant in step up transformer? |
Current
Voltage
Power
Heat
|
16 |
In a coil current change from 2 to 4 A in .05 s. If the average induced emf is 8V then coefficient of self-inductance is: |
0.2 henry
0.1 henry
0.8 henry
0.04 henry
|
17 |
The induced emf in a coil is proportional to: |
Magnetic flux through a coil
Rate of change of magnetic flux through the coil
Area of the coil
Product of magnetic flux and area of the coil
|
18 |
What is the coefficient of mutual inductance, when the magnetic flux changes by 2 X 10-2Wb, and change in current is 0.01 A? |
2 H
3 H
1/2 H
Zero
|
19 |
The device in which induced emf is statically induced emf is: |
Transformer
AC generator
Alternator
Dynamo
|
20 |
For inducting emf in a coil the basic requirement is that: |
Flux should link the coil
Change in flux should link the coil
Coil should form a closed loop
Both B and C are true
|
21 |
Referring to above figure, due to change in current in the coil P, the change in magnetic flux |
Is associated with coil P
Is associated with coil S
Causes and induced current in coil S
All of these
None of these
|
22 |
Referring to above figure, current in coil P falls from its maximum value to zero |
At the instant the switch is closed
At the instant the switch is opened
When switch is kept open
When switch is kept closed
None of these
|
23 |
Referring to above figure, current in the coil P grows from zero to its maximum value |
At the instant the switch is closed
At the instant the switch is opened
When switch is kept open
All of above
Neither of above
|
24 |
A coil of constant area is placed in a constant magnetic field. An induced current is produced in the coil when |
The coil is distorted
The coil is rotated
The coil is neither distorted nor rotated
Both A and B
None of these
|
25 |
Instead of moving the coil towards a magnet, the magnet is moved towards the coil with the same speed. The galvanometer shows current |
Of same magnitude in the same direction
Of different magnitude in the same direction
Of same magnitude but in opposite direction
Of different magnitude in the opposite direction
None of these
|
26 |
When there is no relative motion between the magnet and coil, the galvanometer indicated |
No current in the circuit
An increasing current
A decreasing current
A constant current
Either B or C
|
27 |
The magnitude of induced emf depends upon the |
Rate of decrease of magnetic field
Rate of change of magnetic field
Rate of increase of magnetic flux
Constancy of magnetic field
None of these
|
28 |
Michael Faraday and Joseph Henry belong respectively to |
USA and England
England and France
England and USA
USA and France
None of these
|
29 |
In magnet-coil experiment, emf can be produced by |
Keeping the coil stationary and moving the magnet
Keeping the magnet stationary and moving
Relative motion of the loop and magnet
Any one of above
All above
|
30 |
The induced current in the loop can be Increased by |
Using a stronger magnetic field
Moving the loop faster
Replacing the loop by a coil of many turns
All above
Both A and B
|