Question

An elliptical loop having resistance $R$, of semi major axis $a$ , and semi minor axis $b$  is placed in a magnetic field as shown in the figure. If the loop is rotated about the $x$-axis with angular frequency $\omega$, the average power loss in the loop due to Joule heating is :

JEE Main 2020 (03 Sep Shift 1)

Options

• A: $\frac{{\pi }^2{a}^2{b}^2{B}^2{\omega }^2}{2R}$
• B: zero
• C: $\frac{\pi \mathrm{bB}\omega }{\mathrm{R}}$
• D: $\frac{{\pi }^2{a}^2{b}^2{B}^2{\omega }^2}{R}$

Question

Five equal resistances are connected in a network as shown in figure. The net resistance between the points $A$ and $B$ is :

JEE Main 2021 (26 Feb Shift 1)

Options

• A: $R$
• B: $\frac{R}{2}$
• C: $\frac{3R}{2}$
• D: $2R$

Question

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of $1 / \theta$ vs the resistance $(\mathrm{R})$ of the resistance box is shown in the figure. The figure of merit of the galvanometer is _____ $\times 10^{-1} \mathrm{~A} /$ division. [The source has emf 2V]

JEE Main 2024 (05 Apr Shift 1)

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Question

A Copper $\left(\mathrm{Cu}\right)$ rod of length $25 \mathrm{cm}$ and cross-sectional area $3{ \mathrm{mm}}^2$ is joined with a similar Aluminium $\left(\mathrm{Al}\right)$ rod as shown in figure. Find the resistance of the combination between the ends $A$ and $B.$

(Take resistivity of Copper $=1.7\times {10}^{-8} \mathrm{\Omega m}$, Resistivity of aluminium $=2.6\times {10}^{-8} \mathrm{\Omega m}$)

JEE Main 2021 (22 Jul Shift 1)

Options

• A: $2.170 \mathrm{m\Omega }$
• B: $1.420 \mathrm{m\Omega }$
• C: $0.0858 \mathrm{m\Omega }$
• D: $0.858 \mathrm{m\Omega }$

Question

In the figure shown, the current in the $10 \mathrm{V}$ battery is close to :

JEE Main 2020 (06 Sep Shift 2)

Options

• A: $0.71 \mathrm{A}$ from positive to negative terminal
• B: $0.42 \mathrm{A}$ from positive to negative terminal 
• C: $0.21 \mathrm{A}$ from positive to negative terminal
• D: $0.36 \mathrm{A}$ from negative to postive terminal 

Question

The current density in a cylindrical wire of radius $4 \mathrm{mm}$ is $4\times {10}^6 \mathrm{A} {\mathrm{m}}^{-2}$. The current through the outer portion of the wire between radial distances $\frac{R}{2}$ and $R$ is _____ $\pi \mathrm{A}$.

JEE Main 2022 (27 Jun Shift 1)

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Question

In the given figure, a battery of emf $E$ is connected across a conductor $PQ$ of length $l$ and different area of cross-sections having radii $r_1$ and $r_2\left(r_2<r_1\right).$

Choose the correct option as one moves from $P$ to $Q$.

JEE Main 2021 (27 Jul Shift 1)

Options

• A: Drift velocity of electron increases.
• B: Electric field decreases.
• C: Electron current decreases.
• D: All of these

Question

A wire of resistance $20 \Omega$ is divided into 10 equal parts, resulting pairs. A combination of two parts are connected in parallel and so on. Now resulting pairs of parallel combination are connected in series. The equivalent resistance of final combination is _____ $\Omega$.

JEE Main 2024 (05 Apr Shift 2)

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Question

The equivalent resistance of the given circuit between the terminals $A$ and $B$ is :

JEE Main 2021 (31 Aug Shift 2)

Options

• A: $0 \mathrm{\Omega }$
• B: $\frac{9}{2} \mathrm{\Omega }$
• C: $3 \mathrm{\Omega }$
• D: $1 \mathrm{\Omega }$

Question

A square-shaped wire with a resistance of each side $3 \mathrm{\Omega }$ is bent to form a complete circle. The resistance between two diametrically opposite points of the circle in a unit of $\mathrm{\Omega }$ will is,  _____.

JEE Main 2021 (31 Aug Shift 1)

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Question

For the circuit shown, the value of current at time $t=3.2 \mathrm{s}$ will be ______ $\mathrm{A}$.

[Voltage distribution $\mathrm{V}\left(\mathrm{t}\right)$ is shown by Fig. $\left(1\right)$ and the circuit is shown in Fig. $\left(2\right)$]

JEE Main 2021 (27 Jul Shift 2)

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Question

The current flowing through $R_2$ is :

JEE Main 2023 (11 Apr Shift 2)

Options

• A: $\frac{2}{3} \mathrm{A}$
• B: $\frac{1}{2} \mathrm{A}$
• C: $\frac{1}{3} \mathrm{A}$
• D: $\frac{1}{4} \mathrm{A}$

Question

A meter bridge setup is shown in the figure. It is used to determine an unknown resistance $R$ using a given resistor of $15 \mathrm{\Omega }$. The galvanometer $\left(G\right)$ shows null defection when tapping key is at $43 \mathrm{cm}$ mark from end $A$. If the end correction for end $A$ is $2 \mathrm{cm}$, then the determined value of $R$ will be $\mathrm{\Omega }$.

JEE Main 2022 (28 Jun Shift 1)

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Question

A galvanometer of resistance $100 \Omega$ when connected in series with $400 \Omega$ measures a voltage of upto $10 \mathrm{~V}$. The value of resistance required to convert the galvanometer into ammeter to read upto $10 \mathrm{~A}$ is $x \times 10^{-2} \Omega$. The value of $x$ is :

JEE Main 2024 (05 Apr Shift 2)

Options

• A: $2$
• B: $800$
• C: $20$
• D: $200$

Question

In the experiment of Ohm's law, a potential difference of $5.0 \mathrm{V}$ is applied across the end of a conductor of length $10.0 \mathrm{cm}$ and diameter of $5.00 \mathrm{mm}.$ The measured current in the conductor is $2.00 \mathrm{A}.$ The maximum permissible percentage error in the resistivity of the conductor is :-

JEE Main 2021 (18 Mar Shift 1)

Options

• A: $3.9$
• B: $8.4$
• C: $7.5$
• D: $3.0$

Question

A student is provided with a variable voltage source $V$, a test resistor $R_T=10\Omega$, two identical galvanometers $G_1$ and $G_2$ and two additional resistors, $R_1=10M\Omega$ and $R_2=0.001\Omega$. For conducting an experiment to verify ohm's law, the most suitable circuit is:

JEE Main 2023 (06 Apr Shift 2)

Options

• A:

  

• B:

  

• C:

  

• D:

  

Question

The current $I_1$ (in $A$ ) flowing through $1\mathrm{\Omega }$ resistor in the following circuit is:

JEE Main 2020 (07 Jan Shift 1)

Options

• A: $0.4$
• B: $0.5$
• C: $0.2$
• D: $0.25$

Question

The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance of $2 \mathrm{\Omega }$. The value of internal resistance of each cell is

JEE Main 2022 (29 Jun Shift 2)

Options

• A: $2 \mathrm{\Omega }$
• B: $4 \mathrm{\Omega }$
• C: $6 \mathrm{\Omega }$
• D: $8 \mathrm{\Omega }$

Question

In the given figure, the value of $V_0$ will be _____ $\mathrm{V}$.

JEE Main 2022 (25 Jul Shift 1)

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Question

Twelve wires each having resistance $2 \Omega$ are joined to form a cube. A battery of $6 \mathrm{~V}$ emf is joined across point $a$ and $c$. The voltage difference between $e$ and $f$ is ______V.

JEE Main 2024 (04 Apr Shift 1)

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Question

In a meter bridge experiment $S$ is a standard resistance. $R$ is a resistance wire. It is found that balancing length is $l=25\mathrm{}\mathrm{c}\mathrm{m}.$ If $R$ is replaced by a wire of hall length and half diameter that of $R$ of same material, then the balancing distance $l\text{'}$ (in $\mathrm{c}\mathrm{m}$ ) will now be ______________.

JEE Main 2020 (09 Jan Shift 2)

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Question

The total current supplied to the circuit as shown in figure by the $5 \mathrm{V}$ battery is _____ $\mathrm{A}$.

JEE Main 2022 (25 Jun Shift 1)

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Question

An aluminium wire is stretched to make its length, $0.4\%$ larger. The percentage change in resistance is

JEE Main 2022 (26 Jun Shift 1)

Options

• A: $0.4\%$
• B: $0.2\%$
• C: $0.8\%$
• D: $0.6\%$

Question

Given below are two statements :
Statement I : A uniform wire of resistance $80 \mathrm{\Omega }$ is cut into four equal parts. These parts are now connected in parallel. The equivalent resistance of the combination will be $5 \mathrm{\Omega }$.

Statement II : Two resistance $2R$ and $3R$ are connected in parallel in an electric circuit. The value of thermal energy developed in $3R$ and $2R$ will be in the ratio $3:2$.

In the light of the above statements, choose the most appropriate answer from the options given below

JEE Main 2022 (28 Jul Shift 2)

Options

• A: Both statement I and statement II are correct
• B: Both statement I and statement II are incorrect
• C: Statement I is correct but statement II is incorrect
• D: Statement I is incorrect but statement II is correct.

Question

Resistance are connected in a meter bridge circuit as shown in the figure. The balancing length $l_1$ is $40 \mathrm{cm}$. Now an unknown resistance $x$ is connected in series with $P$ and new balancing length is found to be $80 \mathrm{cm}$ measured from the same end. Then the value of $x$ will be _____ $\mathrm{\Omega }$.

JEE Main 2022 (26 Jul Shift 1)

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