Hans Christian Oersted and Ampere discovered that electric current flowing through a conductor produces a magnetic field around it. Michael Faraday thought that the reverse effect of that should also be true. i.e A magnetic field must produce an electric current. Electromagnetic induction is defined as the process of producing an induced current in a circuit by changing the number of magnetic lines of force that are passing through it.
Contents
- 1 In a purely inductive circuit
- 2 The magnitude of the induced EMF in a conductor depends on
- 3 A solenoid having 500 turns develops an average induced voltage of 60 V. Over what time interval should a flux change of 0.06 Wb occur inorder to produce such a voltage
- 4 The coefficient of coupling between two air core coils depends on
- 5 The law/rule which gives the polarity of the induced EMF
- 6 If current in conductor increases then according to Lenz’s law self-induced voltage will
- 7 The inductor having least eddy current losses is
- 8 The polarity of the induced voltage can be determined using the left-hand generator rule.
- 9 The circuit element that will oppose the change in current
- 10 The feature of coil by which a counter EMF is induced in it when the current through the coil changes is known as
- 11 A core of a coil has length of 200 mm. The inductance of coil is 6 mH. If core length is doubled, while keeping all other quantities same, the inductance will be
In a purely inductive circuit
In a purely inductive circuit
- Actual power of the circuit is zero
- Any capacitance even if present in the circuit will not be charged
- Apparent power is zero
- Relative power is zero
Correct answer: 1. Actual power of the circuit is zero
The magnitude of the induced EMF in a conductor depends on
The magnitude of the induced EMF in a conductor depends on
- Amount of flux cut
- Amount of flux linkages
- Flux density of the magnetic field
- Rate of change of flux-linkages
Correct answer: 4. Rate of change of flux-linkages
A solenoid having 500 turns develops an average induced voltage of 60 V. Over what time interval should a flux change of 0.06 Wb occur inorder to produce such a voltage
A solenoid having 500 turns develops an average induced voltage of 60 V. Over what time interval should a flux change of 0.06 Wb occur inorder to produce such a voltage
- 0.1 s
- 0.325 s
- 0.5 s
- 5 s
Correct answer: 3. 0.5 s
The coefficient of coupling between two air core coils depends on
The coefficient of coupling between two air core coils depends on
- Self-inductance of two coils only
- Mutual inductance and self inductance of two coils
- Mutual inductance between two coils only
- None of these
Correct answer: 2. Mutual inductance and self inductance of two coils
The law/rule which gives the polarity of the induced EMF
The law/rule which gives the polarity of the induced EMF
- Biot-Savart Law
- Lenz’s Law
- Ampere’s circuital Law
- Fleming’s right-hand Rule
Correct answer: 2. Lenz’s Law
If current in conductor increases then according to Lenz’s law self-induced voltage will
If current in conductor increases then according to Lenz’s law self-induced voltage will
- Aid the applied voltage
- Aid the increasing current
- Produce current opposite to the increasing current
- Tend to decrease the amount of current
Correct answer: 3. Produce current opposite to the increasing current
The inductor having least eddy current losses is
The inductor having least eddy current losses is
- Air core
- Iron core
- Laminated iron core
- Powdered iron core
Correct answer: 1. Air core
The polarity of the induced voltage can be determined using the left-hand generator rule.
The polarity of the induced voltage can be determined using the left-hand generator rule.
- No
- Yes
Correct answer: 2. Yes
The circuit element that will oppose the change in current
The circuit element that will oppose the change in current
- Capacitance
- Inductance
- Resistance
- All of these
Correct answer: 2. Inductance
The feature of coil by which a counter EMF is induced in it when the current through the coil changes is known as
The feature of coil by which a counter EMF is induced in it when the current through the coil changes is known as
- Capacitance
- Mutual inductance
- Self-inductance
- Series aiding inductance
Correct answer: 3. Self-inductance
A core of a coil has length of 200 mm. The inductance of coil is 6 mH. If core length is doubled, while keeping all other quantities same, the inductance will be
A core of a coil has length of 200 mm. The inductance of coil is 6 mH. If core length is doubled, while keeping all other quantities same, the inductance will be
- 0.5 mH
- 1 mH
- 3 mH
- 4.6 mH
Correct answer: 3. 3 mH