EASY

Earn 100

A step-up transformer is used on $120 V$ line to provide a P.D of $2400 V$ . If the number of turns in the primary is $75$ , then the number of turns in the secondary shall be,

50% studentsanswered this correctly

Important Questions on Alternating Current

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer is used to light a

100 W,

110 V

lamp from a

220 V

supply. If the supply current is

0.6 A,

the efficiency of the transformer is

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

An ideal transformer has $500$ and $5000$ turn in primary and secondary windings, respectively. If the primary voltage is connected to a $6 V$ DC battery, then the secondary voltage is:

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

Which of the following remain constant in a transformer ?

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer has efficiency

80 %

. It works at

5 kW

and

150 V

. If the secondary voltage is

240 V

, the secondary current is

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A power transmission line feeds input power at

2300 V

to a step down transformer with its primary windings having

4000

turns. The output power is delivered at

230 V

by the transformer. If the current in the primary of the transformer is

5 A

and its efficiency is

90 %

, the output current would be:

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

For the given circuit, comment on the type of transformer used :

Question Image

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A step-up transformer operates on a

230 V

line and a load current of

2 A

. The ratio of primary and secondary windings is

1 : 25

. Then the current in the primary is

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer is used to glow a

140 W - 240 V

bulb at

240 V

AC. If current in the primary coil is

0.7 A

, then the efficiency of the transformer is

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer having efficiency of

90 %

is working on

200 V

and

3 k W

power supply. If the current in the secondary coil is

6 A

the voltage across the secondary coil and the current in the primary coil respectively are:

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer operates at

V_{p} = 6 kV

on the primary side and supplies electric energy at

V_{S} = 220 V

to a number of houses in a town. If the total power consumption of the town is

7.2 kW

, the current (in amperes) in the primary is

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A primary coil is connected with an

A C

source and a bulb is connected with the secondary coil. The voltage across the bulb is

6.0 V

and the current through the bulb is

0.4 A

, The turns ratio is

5 : 1 (Np : Ns = 5 : 1)

. Calculate the current in the primary coil.

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A power transmission line feeds input power at

2300 V

to a step-down transformer with its primary windings having

4000

turns giving the output power at

230 V

. If the current in the primary coil of the transformer is

5 A

and its efficiency is

90 %

, the output current would be:

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A step down transformer connected to an ac mains supply of

220 V

is made to operate at

11 V, 44 W

lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A step-down transformer has turn ratio

20 : 1

. If

8 V

is applied across

0.4 Ω

secondary then the primary current will be

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

How much current is drawn by the primary coil of a transformer, which steps down

220 V

55 V

to operate a device with an impedance of

275 Ω ?

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A step-up transformer operates on a

230 V

line and supplies current of

2 A

to a load. The ratio of the primary and secondary windings is

1 : 25

. The current in the primary coil is

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer is employed to

EASY

Physics>Electricity and Magnetism>Alternating Current>Transformer

A current of

6 A

is flowing at

220 V

in the primary coil of a transformer. If the voltage produced in the secondary coil is

1100 V

and

40 %

of power is lost, then the current in the secondary coil will be:

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer consisting of

300

turns in the primary and

150

turns in the secondary gives output power of

2.2 k W

. If the current in the secondary coil is

10 A

, then the input voltage and current in the primary coil are:

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>Transformer

A transformer of efficiency

90 %

has turns ratio

10 : 1 .

If the voltage across the primary is

220 V

and current in the primary is

0.5 A,

then the current in secondary is

A step-up transformer is used on 120 V line to provide a P.D of 2400 V. If the number of turns in the primary is 75, then the number of turns in the secondary shall be,

Important Questions on Alternating Current

Learn and Prepare for any exam you want !

A step-up transformer is used on $120 V$ line to provide a P.D of $2400 V$ . If the number of turns in the primary is $75$ , then the number of turns in the secondary shall be,