New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 6

EASY

12th CBSE

IMPORTANT

Earn 100

The coil of a pivoted‐type galvanometer has $50$ tums and encloses an area of $6 m^{2}$ . The magnetic field in the region in which the coil swings is $0.01 T$ and is radial. The torsional constant of the hair spring is $1 .0 \times 10^{- 8} {Nmdeg}^{- 1}$ . Find the angular deflection of the coil for a current of $1 m A$ .

Important Questions on Magnetic Effect of Current

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 7

A rectangular coil of area

8 \times 10^{- 4} m^{2}

is suspended freely in a radial magnetic field of induction

2 \times 10^{- 2} Wb m^{- 2}

. When a current of

5 μ A

is passed through the coil, it deflects through

60 °

. The torsional constant of the suspension is

3 .821 \times 10^{- 9} N m {rad}^{- 1}

Find the number of turns of the coil.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 8

A galvanometer needs

25 mV

for a full scale deflection of

50

divisions. Find its voltage sensitivity. What must be its resistance if its current sensitivity is

1 div / 20 μA

?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 9

If the current sensitivity of a moving coil galvanometer is increased by

20 %

, its resistance also increases by

1.5

times. How will the voltage sensitivity of the galvanometer be affected?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 10

Compare the current sensitivity and voltage sensitivity of the following moving coil galvanometers: $M_{1}$ and $M_{2}$ :

$N_{1} = 30, A_{1} = 1 .5 \times 10^{- 3} m^{2}$ ,

$B_{1} = 0 .25 T, R_{1} = 20 Ω$ ,

$N_{2} = 35, A_{2} = 2 .0 \times 10^{- 3} m^{2}$ ,

$B_{2} = 0 .25 T, R_{2} = 30 Ω$ .

You are given that the springs in the two meters have the same torsional constants.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 1

A galvanometer has a resistance of

96 Ω

and it is desired to pass

4 %

of the total current through it. Calculate the value of shunt resistance.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 2

A galvanometer has a resistance of

50 Ω

. A resistance of

5 Ω

is connected across its terminals. What part of the total current will flow through the galvanometer?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 3

How will you convert

1 mA

full scale deflection galvanometer of resistance

100

ohms into an ammeter to read

1 A

(full scale deflection) and into a voltmeter to read

1

volt (full scale deflection).

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems For Practice>Q 4

A moving coil galvanometer of resistance

10 Ω

produces full scale deflection, when a current of

25 m A

is passed through it. Describe showing full calculations, how will you convert the galvanometer into (i) a voltmeter reading up to

120 V

and (ii) an ammeter reading up to

20 A

.