A small current element I d l → , with d l → = 2 k ^ mm and I = 2 A is centred at the origin. Find magnetic field d B → at the following points: (i) On the x -axis at x = 3 m .

Given, I = 2 A x = 3 m d B = μ 0 I d l × r ⇀ 4 π r 3 d B = 10 - 7 × 2 × 3 4 π × 3 3 = 0 . 44 × 10 - 7 T ^ 0 . 44 × 10 - 7 j ^ T

State Ampere's circuital law connecting the line integral of B → over a closed path to the net current crossing the area bounded by the path.

Ampere's circuital law state that the line integral of the magnetic field B → around any closed path is equal to go times the total current I threading the closed path. ∮ B → . d l → = μ 0 I

EASY

12th CBSE

IMPORTANT

Earn 100

A moving coil galvanometer consists of a rectangular coil of $N$ turns, each of area $A$ , suspended in a radial magnetic field of flux density $B$ . Derive the expression for the torque on the coil, when current $I$ passes through it. Draw a suitable labelled diagram.

Important Questions on Magnetic Effect of Current

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems for Practice>Q 1

A wire placed along east-west direction carries a current of

10 A

from west to east direction. Determine the magnetic field due to a

1.8 cm

piece of wire at a point

300 cm

north-east from the piece.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Problems for Practice>Q 2

A small current element $I \vec{d l}$ , with $\vec{d l} = 2 \hat{k} mm$ and $I = 2 A$ is centred at the origin. Find magnetic field $\vec{d B}$ at the following points:

(i) On the $x$ -axis at $x = 3 m$ .

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 1

Write any two important points of similarities and differences each between Coulomb's law for the electrostatic field and Biot-Savart's law for the magnetic field.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 5

State Ampere's circuital law connecting the line integral of

\vec{B}

over a closed path to the net current crossing the area bounded by the path.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 5

Explain carefully why the derivation as in

(b)

is not valid for magnetic field in a plane normal to a current-carrying straight wire of finite length and passing through the midpoint of the axis.

MEDIUM

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 6

Show how Biot-Savart law can be alternatively expressed in the form of Ampere's circuital law. Use this law to obtain the expression for the magnetic field inside a solenoid of length

' l'

, cross-sectional area

' A'

having

' N'

closely wound turns and carrying a steady current

' I'

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 6

Sketch the magnetic field lines for a finite solenoid. Explain why the field at the exterior midpoint is weak while at the interior, it is uniform and strong.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 4 - Magnetic Effect of Current>Text Based Exercises>Q 14

Two straight long parallel conductors carry currents

I_{1}

and

I_{2}

in the same direction. Deduce the expression for the force per unit length between them. Depict the pattern of magnetic field lines around them.

A moving coil galvanometer consists of a rectangular coil of N turns, each of area A, suspended in a radial magnetic field of flux density B. Derive the expression for the torque on the coil, when current I passes through it. Draw a suitable labelled diagram.

Important Questions on Magnetic Effect of Current

Learn and Prepare for any exam you want !

A moving coil galvanometer consists of a rectangular coil of $N$ turns, each of area $A$ , suspended in a radial magnetic field of flux density $B$ . Derive the expression for the torque on the coil, when current $I$ passes through it. Draw a suitable labelled diagram.