The magnetic intensity at the centre of a long current carrying solenoid is found to be $1.6 \times 10^{3} \mathrm{Am}^{-1}$. If the number of turns is 8 per cm, then the current flowing through the solenoid is $\_\_\_\_$ A.

JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Magnetic Effects of Current

The magnetic intensity at the centre of a long current carrying solenoid is found to be

1.6 \times 1 0^{3} Am^{- 1}

. If the number of turns is 8 per cm, then the current flowing through the solenoid is

____

Answer: 2

Solution

The magnetic field intensity inside a solenoid is given by

H = ni

, where

n

is the number of turns per unit length and

i

is the current.

Solving for current:

i = \frac{H}{n} = \frac{1.6 \times 1 0 ^{3}}{800} = 2 A

where

n = 8 turns/cm = 800 turns/m

JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Integer answer

Practise more: all JEE Main PYQs on Magnetic Effects of Current →

More JEE Main questions on Magnetic Effects of Current

An infinitely long straight wire carrying current I is bent in a planer shape as shown in the diagram. The radius of the circular part is r . The magnetic field at the centre O of the circular loop is :
JEE Main 2026View solution →
The current passing through a conducting loop in the form of equilateral triangle of side $43 cm$ is 2A. The magnetic field at its centroid is $α \times 1 0^{- 5} T$ . The value of $α$ is ____.
(Given : …
JEE Main 2026View solution →
Three long straight wires carrying current are arranged mutually parallel as shown in the figure. The force experienced by 15 cm length of wire $Q$ is ______.
( $μ_{0} = 4 π \times 1 0^{- 7} T . m / A$ )
JEE Main 2026View solution →
The magnetic field at the centre of a current carrying circular loop of radius $R$ is $16 μ T$ . The magnetic field at a distance $x = 3 R$ on its axis from the centre is ____ $μ T$ .
JEE Main 2026View solution →
Two identical circular loops P and Q each of radius r are lying in parallel planes such that they have common axis. The current through P and Q are I and 4I respectively in clockwise direction as seen from O. The net magnetic field at O is:
JEE Main 2026View solution →
A long cylindrical conductor with large cross section carries an electric current distributed uniformly over its cross-section. Magnetic field due to this current is :
A. maximum at either ends of the conductor and minimum at the midpoint
B. maximum at the axis of the conductor
C …
JEE Main 2026View solution →