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

MEDIUM

Earn 100

Two identical fuses are rated at $10 A$

50% studentsanswered this correctly

Important Questions on Magnetic Fields due to Electric Current

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

A moving coil galvanometer has resistance

50 Ω

and it indicates full deflection at

4 m A

current. A voltmeter is made using this galvanometer and a

5 k Ω

resistance. The maximum voltage, that can be measured using this voltmeter, will be close to:

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

A galvanometer of resistance

100 Ω

has

50

divisions on its scale and has sensitivity of

20 μ A / d i v i s i o n

. It is to be converted to voltmeter with three ranges, of

0 - 2 V, 0 - 10 V

and

0 - 20 V .

The appropriate circuit to do so is:

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

A

B

and

C

are voltmeters of resistance

R

1 .5 R

and

3 R

respectively as shown in the figure. When some potential difference is applied between

X

and

Y

, the voltmeter readings are

V_{A}, V_{B}

and

V_{C}

respectively. Then:
Question Image

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

A moving coil galvanometer allows a full scale current of

10^{- 4} A

. A series resistance of

2 \times 10^{4} Ω

is required to convert the galvanometer into a voltmeter of range

0 - 5 V

. Therefore, the value of shunt resistance required to convert the above galvanometer into an ammeter of range

0 - 10 m A

is:

HARD

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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,

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

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:

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

When a current of

5 mA

is passed through a galvanometer having a coil of resistance

15 Ω

, it shows full-scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range

0 - 10 V

is:

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

The range of an ammeter of resistance

G

can be increased from

I

n I

by connecting

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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:

HARD

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

A galvanometer having a coil resistance

100 Ω

gives a full scale deflection when a current of

1 m A

is passed through it. What is the value of the resistance which can convert this galvanometer into a voltmeter given full scale deflection for a potential difference of

10 V ?

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

In an ammeter

0.2 %

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

G,

the resistance of ammeter will be:

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

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>Magnetic Fields due to Electric Current>Ammeter

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.

EASY

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

10 V

battery with internal resistance

1 Ω

and a

15 V

battery with internal resistance

0.6 Ω

are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to:

Question Image

MEDIUM

Physics>Electricity and Magnetism>Magnetic Fields due to Electric Current>Ammeter

A galvanometer, whose resistance is

50 ohm

, has

25

divisions in it. When a current of

4 \times 10^{- 4}

A passes through it, its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range

2.5 V

it should be connected to a resistance of:

Two identical fuses are rated at 10A

Important Questions on Magnetic Fields due to Electric Current

Learn and Prepare for any exam you want !

Two identical fuses are rated at $10 A$