The range of an ammeter of resistance G can be increased from I to n I by connecting

A series resistance of G n + 1 Ω

A series resistance of G n - 1 Ω

EASY

Earn 100

What does a shunt resistor do?

Important Questions on Current Electricity

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A galvanometer of resistance

100 Ω

requires

10 μA

current for full scale deflection. Now a resistance of

1 Ω

is connected to convert it into an ammeter. The minimum current required to obtain full scale deflection is

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

The range of an ammeter of resistance

G

can be increased from

I

n I

by connecting

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

An ammeter of resistance

1.5 Ω

can measure currents upto

1 A

. The value of shunt resistance to measure current upto

4 A

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

This question has

Statement I

and

Statement II

. Of the four choices given after the Statements, choose the one that best describes the two Statements.

Statement - I :

Higher the range, greater is the resistance of ammeter.

Statement - II :

To increase the range of ammeter, additional shunt needs to be used across it.

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A circuit contains an ammeter, a battery of 30 v and a resistance 40.8 ohm all connected in series. If the ammeter has coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be:

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

50 ohm

galvanometer gets full scale deflection when a current of

0.01 A

pass through the coil. When it is converted to a

10 A

ammeter, the shunt resistance is

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

The deflection in galvanometer falls to $\left(\frac{1}{4}\right)^{\operatorname{th}}$ when it is shunted by $3 Ω$ . If additional shunt of $2 Ω$ is connected to earlier shunt, the deflection in galvanometer falls to

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

An ammeter reads up to

1 A

. Its internal resistance is

0.45 Ω

. To increase the range to

10 A

the value of the required shunt is

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

50 Ω

resistance is connected to a battery of

5 V

. A galvanometer of resistance

100 Ω

is to be used as an ammeter to measure current through the resistance, for this a resistance

r_{S}

is connected to the galvanometer. Which of the following connections should be employed if the measured current is with in

1 %

of the current without the ammeter in the circuit?

HARD

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A moving coil galvanometer, having a resistance

G,

produces full scale deflection when a current

I_{G}

flows through it. This galvanometer can be converted into (i) an ammeter of range 0 to

I_{o} (I_{0} > I_{g})

by connecting a shunt resistance

R_{A}

to it and (ii) into a voltmeter of range 0 to

V (V = G I_{0})

by connecting a series resistance

R_{V}

to it. Then,

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

The deflection in the galvanometer falls to

{(\frac{1}{5})}^{th}

when

4 Ω

resistance is connected in parallel with it. What will be the deflection if an additional resistance of

2 Ω

is connected in parallel with the above shunted galvanometer?

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A galvanometer with its coil resistance

25 Ω

requires a current of

1 mA

for its full deflection. In order to construct an ammeter to read up to a current of

2 A

the approximate value of the shunt resistance should be:

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

How do you convert a moving coil galvanometer into an ammeter?

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A galvanometer having a resistance of

8 Ω

is shunted by a wire of resistance

2 Ω .

If the total current is

1 A,

the part of it passing through the shunt will be

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

Distinguish between ammeter and voltmeter.

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

Consider a galvanometer shunted with

5 Ω

resistance and

2 %

of current passes through it. What is the resistance of the given galvanometer?

EASY

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A galvanometer has a coil of resistance

5 Ω

and requires

15 mA

for full-scale deflection. The shunt resistance needed to convert the galvanometer into an ammeter of the range

0 - 1 A

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

In an ammeter

0.2 %

of main current passes through the galvanometer. If resistance of galvanometer is

G,

the resistance of ammeter will be:

MEDIUM

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is deflection of 40 divisions when $R.B. = 2400 Ω .$ Deflection becomes 20 divisions when resistance taken from resistance box is 4900 Ω. Then we can conclude :

Question Image

Note: This question is awarded as the bonus. Now the question is corrected.

HARD

Physics>Electricity and Magnetism>Current Electricity>Combination of Resistances

In a circuit for finding the resistance of a galvanometer by half deflection method, a

6 V

battery and a high resistance of

11 kΩ

are used. The figure of merit of the galvanometer is

60 μA {division}^{- 1}

. In the absence of shunt resistance, the galvanometer produces a deflection of

θ = 9

divisions when current flows in the circuit. The value of the shunt resistance that can cause the deflection of

\frac{θ}{2}

, is closest to:

What does a shunt resistor do?

Important Questions on Current Electricity

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