A NPN transistor conducts when
1.Both collector and emitter are positive with respect to the base
2.Collector is positive and the emitter is negative with respect to the base
3. Collector is positive and the emitter is at the same potential as the base
4.Both collector and emitter are negative with respect to the base
Posted Date:-2021-12-07 14:46:06
AC generator converts
1.Mechanical energy to electrical energy
2.Electrical energy to mechanical energy
3.Heat energy to mechanical energy
4. maybe maximum or minimum
Posted Date:-2021-12-07 14:21:48
In A.C generator increasing the no. of turns in the coil
1. Decreases the Electromotive force (EMF)
2. Electromotive force (EMF) remains the same
3.Increases the Electromotive force (EMF)
4. Electromotive force (EMF) becomes zero
Posted Date:-2021-12-07 14:02:20
In alternative current generator, AC current reverses its direction
1.10 times per second
2. 20 times per second
3.60 times per second
4. 50 times per second
Posted Date:-2021-12-07 14:20:15
The inductance of the coil is not affected by which of the following?
1.The length of the coil
2.Number of turns
3.The material of the core
4.The diameter of the wire
Posted Date:-2021-12-07 14:28:52
Higher the self-inductance of a coil
1.Lesser its weber-turns
2.Emf induced is low
3.Greater the flux produced
4.Longer the delay in establishing a steady current through it
Posted Date:-2021-12-07 14:25:46
How does an inductor work?
1.Storing energy as a magnetic field.
2. A wire piece is charged
3.Introducing resistance into a circuit
4.Choking off high-frequency ac
Posted Date:-2021-12-07 14:27:16
If the coil is placed perpendicular to field lines then the number of lines passing through the coil is
1.Minimum
2.maximum
3.zero
4.maybe maximum or minimum
Posted Date:-2021-12-07 14:19:18
In a small inductance:
1.Large current flow
2.Energy is stored and released quickly
3.Small current flow
4.Energy is stored and released slowly
Posted Date:-2021-12-07 14:30:08
Mutual inductance between two magnetically coupled coils depends on
1.Permeability of the core material
2.Number of turns of the coils
3.The cross-sectional area of their common core
4.All of the above
Posted Date:-2021-12-07 14:23:59
Name two main parts of an AC generator
1.Stator
2.Rotor
3.Both 1 and 2
4.None of these
Posted Date:-2021-12-07 14:20:48
The combination of the same two inductors (33 mH and 55 mH) connected in parallel without mutual inductance will have a value of
1. 22 mH
2.88 mH
3.1.8 H
4.21 mH
Posted Date:-2021-12-07 14:41:23
The direction of induced emf or current is indicated by
1.Fleming’s left-hand rule
2.Fleming’s right-hand rule
3.Faraday’s law of electromagnetic induction
4.None of these
Posted Date:-2021-12-07 14:23:06
The Electromotive force (EMF) developed by the generator depends upon
1.Area of rotating wire
2.length of rotating wire
3.Radius of wire
4.size of magnet
Posted Date:-2021-12-07 14:07:04
The emitter-base junction of a transistor is ………. Biased while the collector-base junction is ………….
1.Reverse, Forward
2.Reverse, Reverse
3.Forward, forward
4.Forward, reverse
Posted Date:-2021-12-07 14:43:56
The metal detectors installed at airports and other places for security purpose are based on the principle of
1.potential difference
2.electromagnetic difference
3.electromagnetic induction
4.potential energy
Posted Date:-2021-12-07 14:08:38
The phenomenon due to which there is an induced current in one coil due to the current in a neighbouring coil is?
1.Mutual inductance
2.Steady current
3.Electromagnetism
4.Susceptance
Posted Date:-2021-12-07 14:31:50
Three inductance with the values 4 NH, 140 μH, and 5 H are connected in series without mutual inductance. For practical purposes, the net inductance will be very close to
1. 4 NH
2.140 μH
3.5 H
4.None of these
Posted Date:-2021-12-07 14:42:08
What replacement is required to convert an AC generator to DC generator?
1.Concave magnets with horseshoe magnets
2.Armature with coil
3.Slip rings with split rings
4.None of the above
Posted Date:-2021-12-07 14:22:30
What will be the inductance if the iron core is removed from the iron cored coil to make it air-cored coil?
1.More
2.Less
3.The same
4.None
Posted Date:-2021-12-07 14:24:45
Which of the following circuit elements will oppose the change in circuit current?
1.Capacitance
2.Inductance
3.Resistance
4.All of the above
Posted Date:-2021-12-07 14:26:28