HARD

12th CBSE

IMPORTANT

Earn 100

An a.c. circuit consists of a $220 V,$ $50 H z$ supply connected across a $100 Ω$ resistor. What inductance should be connected in the circuit in series with resistance so that the current is reduced to half?

Important Questions on Alternating Current and Electrical Machines

HARD

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 12

A long solenoid connected to a

12 V

d.c. source passes a steady current of

2 A .

When the solenoid is connected to an a.c. source of

12 V

50 H z

, the current flowing is

1 A

. Calculate the inductance of the solenoid.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 13

A choke coil and a resistance are connected in series in an a.c. circuit. A potential difference of

130 V

is applied to the circuit. If the potential difference across the resistance is

50 V

, what should be the potential difference across the choke coil?

HARD

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 14

An emf,

ε = 200 \sin 377 t

volt is applied across an inductance

L

having a resistance of

1.0 Ω

. The maximum current is found to be

10 A

. Find the value of

L

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 16

In the RL-circuit shown in figure, resistance

R = 30 Ω

, reactance

X_{L} = 40 Ω

and peak emf

= 220 V

.
Calculate the (i) impedance

Z .

(ii) phase difference between the emf and current and (iii) the peak current

I_{0}

in the circuit.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 1

A circuit containing a

20 Ω

resistor and

0.1 μ F

capacitor in series is connected to

230 V

a.c. supply of angular frequency

100

rad

s^{- 1}

. What is the impedance of the circuit?

HARD

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 2

A circuit consists of a resistance of

10 Ω

and a capacitance of

0.1 μ F

. If an alternating emf of

100 V

50 H z

is applied, find the current in the circuit.

HARD

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 3

20 W

50 V

, filament is connected in series to an a.c. mains of

250 V

50 H z

. Calculate the value of the capacitor required to run the lamp.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 1 - Alternating Current and Electrical Machines>Problems For Practice>Q 6

A capacitor in series with a resistance of

30 Ω

is connected to a.c. mains. The reactance of the capacitor is

40 Ω

. Calculate the phase difference between the current and the supply voltage of capacitor.

An a.c. circuit consists of a 220V, 50Hz supply connected across a 100Ω resistor. What inductance should be connected in the circuit in series with resistance so that the current is reduced to half?

Important Questions on Alternating Current and Electrical Machines

Learn and Prepare for any exam you want !

An a.c. circuit consists of a $220 V,$ $50 H z$ supply connected across a $100 Ω$ resistor. What inductance should be connected in the circuit in series with resistance so that the current is reduced to half?