1
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A circular coil, carrying current, has radius $R$. The distance from the centre of the coil on the axis where the magnetic induction will be $\frac{1}{27}$ th of its value at the centre of the coil is

A

$2 \sqrt{2} R$

B

$3 \sqrt{2} R$

C

$3 R$

D

$2 \sqrt{3} R$

2
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A square of side $L$ lies in the $x-y$ plane,where the magnetic field is given by $B=B_0(2 \hat{i}+3 \hat{j}+4 \hat{k})$ where $B_0$ is constant.The magnetic flux passing through the square is $L$

A

$5 B_0 L^2$

B

$3 B_0 L^2$

C

$2 B_0 L^2$

D

$4 B_0 L^2$

3
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A resistor of resistance'$R$'draws power'$P$'when connected to an AC source.If an inductance is now placed in series with $R$ ,such that the impedance of the circuit becomes'$Z$',the power drawn will be

A

$P\left(\frac{R}{Z}\right)$

B

$P\left(\frac{R}{Z}\right)^3$

C

$P\left(\frac{R}{Z}\right)^2$

D

$P \sqrt{\frac{Z}{R}}$

4
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A simple pendulum of length $l$ has a bob of mass $m$ ,with a charge $q$ .On it a vertical sheet of charge, with surface charge density'$\sigma$'passes through the point of suspension.At equilibrium,if the string makes an angle $\theta$ with the vertical,then

A

$\tan \theta=\frac{\sigma q}{2 \varepsilon_0 m g}$

B

$\tan \theta=\frac{\sigma q}{\varepsilon_0 m g}$

C

$\cot \theta=\frac{\sigma q}{2 \varepsilon_0 m g}$

D

$\cot \theta=\frac{\sigma q}{\varepsilon_0 m g}$