Electrical Instruments

Interactive Feed

A microammeter has a resistance of $100 Ω$ and full scale range of $50 μ A$ . It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination(s)

50 V

range with

10 k Ω

resistance in series

(B)

10 V

range with

200 k Ω

resistance in series

(C)

5 mA

range with

1 Ω

resistance in parallel

(D)

10 mA

range with

1 Ω

resistance in parallel

JEE Main 2011

LEVELJEE Main

A meter bridge is set-up as shown in figure, to determine an unknown resistance $X$ using a standard $10 Ω$ resistor. The galvanometer shows null point when tapping-key is at $52 cm$ mark. The end-corrections are $1 cm$ and $2 cm$ respectively for the ends $A$ and $B$ . The determined value of $X$ is

(A)

10.2 Ω

(B)

10.6 Ω

(C)

10.8 Ω

(D)

11.1 Ω

JEE Advanced 2014

LEVELJEE Advanced

A galvanometer gives full scale deflection with $0.006 A$ current. By connecting it to a $4990 Ω$ resistance, it can be converted into a voltmeter of range $0 - 30 V$ . If connected to a $\frac{2 n}{249} Ω$ resistance, it becomes an ammeter of range $0 - 1.5 A$ . The value of $n$ is

LEVELJEE Main

A thin uniform wire $A B$ of length $1 m$ , an unknown resistance $X$ and a resistance of $12 Ω$ are connected by thick conducting strips, as shown in the figure. A battery and galvanometer (with a sliding jockey connected to it are also available). Connections are to be made to measure the unknown resistance $X$ using the principle of Wheatstone bridge. Answer the following questions. (a) Are there positive and negative terminals on the galvanometer? (b) Copy the figure in your answer book and show the battery and the galvanometer (with jockey) connected at appropriate points. (c) After appropriate connections are made, it is found that no deflection takes place in the galvanometer when the sliding jockey touches the wire at a distance of $60 cm$ from $A$ . Obtain the value of the resistance $X$ .

JEE Advanced 2016

LEVELJEE Main

Consider two identical galvanometers and two identical resistors with resistance $R$ . If the internal resistance of the galvanometers $R_{c} < \frac{R}{2}$ , which of the following statement(s) about any one of the galvanometers is (are) true?

* Multiple Correct Options

(A)

The maximum voltage range is obtained when all the components are connected in series

(B)

The maximum voltage range is obtained when the two resistors and one galvanometer are connected in series, and the second galvanometer is connected in parallel to the first galvanometer

(C)

The maximum current range is obtained when all the components are connected in parallel

(D)

The maximum current range is obtained when the two galvanometers are connected in series, and the combination is connected in parallel with both the resistors

LEVELJEE Main

In the circuit shown $P \neq = R$ , the reading of galvanometer is same with switch $S$ open or closed. Then

(A)

I_{R} = I_{G}

(B)

I_{P} = I_{G}

(C)

I_{Q} = I_{G}

(D)

I_{Q} = I_{R}

JEE Main 2007

LEVELJEE Main

A resistance of $2 Ω$ is connected across one gap of a meter-bridge (the length of the wire is 100 cm) and an unknown resistance, greater than $2 Ω$ , is connected across the other gap. When these resistances are interchanged, the balance point shifts by 20 cm. Neglecting any corrections, the unknown resistance is

(A)

3 Ω

(B)

4 Ω

(C)

5 Ω

(D)

6 Ω

LEVELJEE Main

Show by diagram, how can we use a rheostat as the potential divider ?

JEE Advanced 2010

LEVELJEE Advanced

To verify Ohm's law, a student is provided with a test resistor $R_{T}$ , a high resistance $R_{1}$ , a small resistance $R_{2}$ , two identical galvanometers $G_{1}$ and $G_{2}$ , and a variable voltage source $V$ . The correct circuit to carry out the experiment is

In the shown arrangement of the experiment of the meter bridge if $A C$ corresponding to null deflection of galvanometer is $x$ , what would be its value if the radius of the wire $A B$ is doubled ?

(A)

x

(B)

x /4

(C)

4 x

(D)

2 x

JEE Advanced 2005

LEVELJEE Main

$R_{1}, R_{2}, R_{3}$ are different values of $R$ . Further, $A, B$ and $C$ are the null points obtained corresponding to $R_{1}, R_{2}$ and $R_{3}$ respectively. For which resistor, the value of $X$ will be the most accurate and why?

LEVELJEE Main

A moving coil galvanometer of resistance $100Ω$ is used as an ammeter using a resistance $0.1Ω$ . The maximum deflection current in the galvanometer is $100 μ A$ . Find the current in the circuit, so that the ammeter shows maximum deflection.

(A)

100.1 mA

(B)

1000.1 mA

(C)

10.01 mA

(D)

1.01 mA

JEE Advanced 2004

LEVELJEE Main

Draw the circuit for experimental verification of Ohm's law using a source of variable DC voltage, a main resistance of $100 Ω$ , two galvanometers and two resistances of values $1 0^{6} Ω$ and $1 0^{- 3} Ω$ respectively. Clearly show the positions of the voltmeter and the ammeter.

JEE Advanced 1982

LEVELJEE Main

Two resistors, $400Ω$ and $800Ω$ are connected in series with a $6 V$ battery. It is desired to measure the current in the circuit. An ammeter of $10Ω$ resistance is used for this purpose. What will be the reading in the ammeter? Similarly, if a voltmeter of $1000Ω$ resistance is used to measure the potential difference across the $400Ω$ resistor, what will be the reading in the voltmeter?

JEE Main 2004

LEVELJEE Main

For the post office box arrangement to determine the value of unknown resistance, the unknown resistance should be connected between

(A)

B

and

C

(B)

C

and

D

(C)

A

and

D

(D)

B_{1}

and

C_{1}

JEE Advanced 2014

LEVELJEE Advanced

During an experiment with a meter bridge, the galvanometer shows a null point when the jockey is pressed at $40.0 cm$ using a standard resistance of $90 Ω$ , as shown in the scale used in the meter bridge is $1 mm$ . The unknown resistance is

(A)

60 \pm 0.15 Ω

(B)

135 \pm 0.56 Ω

(C)

60 \pm 0.25 Ω

(D)

135 \pm 0.23 Ω

LEVELJEE Advanced

An electrical circuit is shown in figure. Calculate the potential difference across the resistor of $400 Ω$ as will be measured by the voltmeter $V$ of resistance $400 Ω$ either by applying Kirchhoff's rules or otherwise.

JEE Main 2008

LEVELJEE Main

Assertion: In a meter bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. Reason: Resistance of a metal increases with increase in temperature.

(A)

If Assertion is true, Reason is true; Reason is the correct explanation for Assertion

(B)

If Assertion is true, Reason is true; Reason is not a correct explanation for Assertion

(C)

If Assertion is true; Reason is false

(D)

If Assertion is false; Reason is true

JEE Advanced 2020

LEVELJEE Advanced

In the balanced condition, the values of the resistances of the four arms of a Wheatstone bridge are shown in the figure below. The resistance $R_{3}$ has temperature coefficient $0.0004^{\circ} C^{- 1}$ . If the temperature of $R_{3}$ is increased by $100^{\circ} C$ , the voltage developed between S and T will be ______ volt.

JEE Advanced 2019

LEVELJEE Advanced

Two identical moving coil galvanometer have $10 Ω$ resistance and full scale deflection at $2 μ A$ current. One of them is converted into a voltmeter of $100 mV$ full scale reading and the other into an Ammeter of $1 mA$ full scale current using appropriate resistors. These are then used to measure the voltage and current in the Ohm's law experiment with $R = 1000 Ω$ resistor by using an ideal cell. Which of the following statement(s) is/are correct ?

* Multiple Correct Options

(A)

The measured value of

R

will be

978 Ω < R < 982 Ω

(B)

The resistance of the Voltmeter will be

100 k Ω

(C)

The resistance of the Ammeter will be

0.02 Ω

(round off to

2^{nd}

decimal place)

(D)

If the ideal cell is replaced by a cell having internal resistance of

5 Ω

then the measured value of

R

will be more than

1000 Ω

JEE Advanced 2022

LEVELJEE Advanced

Two resistances $R_{1} = X Ω$ and $R_{2} = 1 Ω$ are connected to a wire AB of uniform resistivity, as shown in the figure. The radius of the wire varies linearly along its axis from $0.2 mm$ at A to $1 mm$ at B. A galvanometer (G) connected to the center of the wire, $50 cm$ from each end along its axis, shows zero deflection when A and B are connected to a battery. The value of X is _____.

JEE Advanced 2026

LEVELJEE Advanced

As shown in the figure, the resistance of a galvanometer $G$ can be found by the half-deflection method. Here the resistance $R_{2}$ is adjusted such that when the key $K$ is closed the deflection in the galvanometer becomes half of the value as compared to when $K$ is open. Half-deflection is obtained at $R_{2} = 4 Ω$ and thus the galvanometer resistance is found to be $6 Ω$ . In this half-deflection condition the current (in mA) through the resistor $R_{1}$ is:

JEE Advanced 2021

LEVELJEE Advanced

In order to measure the internal resistance $r_{1}$ of a cell of emf $E$ , a meter bridge of wire resistance $R_{0} = 50 Ω$ , a resistance $R_{0} /2$ , another cell of emf $E /2$ (internal resistance $r$ ) and a galvanometer $G$ are used in a circuit, as shown in the figure. If the null point is found at $l = 72 cm$ , then the value of $r_{1} =_____Ω$ .

JEE Main 2019

LEVELJEE Advanced

In the experimental set up of meter bridge shown in the figure, the null point is obtained at a distance of $40 cm$ from $A$ . If a $10 Ω$ resistor is connected in series with $R_{1}$ , the null point shifts by $10 cm$ . The resistance that should be connected in parallel with $(R_{1} + 10) Ω$ such that the null point shifts back to its initial position is

(A)

60 Ω

(B)

20 Ω

(C)

30 Ω

(D)

40 Ω

LEVELBoard

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

(A)

low resistance in parallel

(B)

high resistance in parallel

(C)

high resistance in series

(D)

low resistance in series

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } In the circuit shown P=R, the reading of galvanometer is same with switch S open or closed. Then

Show by diagram, how can we use a rheostat as the potential divider ?

For the post office box arrangement to determine the value of unknown resistance, the unknown resistance should be connected between

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

In the circuit shown $P \neq = R$ , the reading of galvanometer is same with switch $S$ open or closed. Then