1 |
In the circult, the ammeter reading is 0.5 A . If the resistance of the voltmeter is 180Ohm What is the voltmeter rediang. |
90 V
100 V
180 V
900 V
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2 |
In an induction coil, the secondary emf is. |
Zero at the break of the circuit
Zero during make of the circuit
Very high during make of the circuit.
Very high during break of the circuit
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3 |
A generator running in reverse may be called as. |
A.C. Generator
D.C. generator
Motor
Commutator
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4 |
Which factor remains constant in a transformer. |
Current
Voltage
Power
Frequency
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5 |
If the transformer turns ratio is 2 and the impedance of primary coil is 250 Ohms then the impedance secondary coil will be. |
125 Ohms
250 Ohms
500 Ohms
1000 Ohms
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6 |
If the transformer turns ratio is 2 and the impedance eof primary coil is 250 Ohms then the impedance secondary coil will be. |
125 Ohms
250 Ohms
500 Ohms
1000 Ohms
|
7 |
The long distance transmission of electrical energy is done at. |
High potential and low current
High potential and highs current
Low potential and high current
Low potential and low current
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8 |
Why does a transformer have a core made of iron. |
Iron has a high melting point
Iron is a magnetic material
Iron potential and high current
Iron is a conductor of electricity
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9 |
A step up transformer has a turn ratio of 1:100 A voltage of 20 V is connected across the primary coil What is the secondary voltage. |
0.2 V
5 V
100 V
2000 V
|
10 |
A transformer is needed to convert a mains 240 V supply into a 12 V supply it there are 200 turns on the primary coil, how many turns should there be on the secondary coil. |
100
200
400
600
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11 |
The cause of production of eddy current is the |
Current flowing in a conductor
Current flowing in a insulator
Motion of a conductor in a varying magnetic field
Motion of an insulator in a varying magnetic field
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12 |
Eddy current can be minimized by |
Moving the conductor rapidly
Moving the conductor slowly
Using a metallic core
Using a laminated core
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13 |
A straight copper wire a moved in a uniform magnetic field such that it cuts the magnetic lines of force then. |
emf will not be induced
emf will beinduced
sometimes emf will be induced and sometimes not
The number of turns iin the coil increases
|
14 |
A transformer is used to. |
Convert D.C. into A.C.
Convert A.C. in to D.C.
Obtain A.C. voltage
Enhance the power
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15 |
A device which converts electrical energy into mechanical energy is called. |
A.C generator
D.C. generator
Motor
Commutator
|
16 |
In what form is the energy stored in an inductor. |
Magnetic
electrostatic
Magnetic and electrostatic
All of the above
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17 |
Under which of the following conditions current in a circuit is wattles. |
When inductance in the circuit is zero
When resistance in the circuit is zero
When current is alternating
When resistance and inductance both are zero
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18 |
The device in the circuit that consume electrical energy are known as. |
Resistors
Capacitors
Fuses
Load
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19 |
The core of a transfer is made of iron because |
Iron is a good electric material
Iron is cheaper than copper
Iron is easily magnetized and demagnetized
Iron makes a good permanent magnet
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20 |
Direct current generators use. |
Coiled rings
Split rings
slip rings
solenoid rings
|