List of top Physics Questions on Magnetic Field

A circular coil of radius \(R\) carries a current \(I\). The magnetic field at its centre is \(B\). At what distance from the centre on the axis of the coil will the magnetic field be \(B/8\)?

A proton \((q = 1.6 \times 10^{-19}\,C)\) enters a magnetic field of \(2\,T\) with a velocity of \(3 \times 10^6\,\text{m/s}\) perpendicular to the field. Find the magnetic force acting on the proton.

A charged particle moves in a magnetic field \(B\) with velocity components both along and perpendicular to \(B\). What is its path?

Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side \( a \), kept on a table and carry equal current \( I \). The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude:

What happens to the magnetic field at the center of a circular coil if the number of turns is doubled while current remains constant?

A particle of charge 10 times that of an electron is revolving in a circular path of radius $0.5 \text{ m}$. If the frequency of rotation is 10 rotations per second, the magnetic field at the centre of the circular path is approximately ($\mu_0 = 4\pi \times 10^{-7} \text{ Hm}^{-1}$)}

If a straight infinitely long horizontal wire carries a current of 50 A in east-west direction, then the magnitude of the magnetic field due to the current at a vertical distance of 2 m above the wire is:

The magnetic field at the centre of a circular coil of radius $r$ carrying a current $I$ is proportional to

The force experienced by a charge $q$ moving with velocity $v$ in a magnetic field $B$ is maximum when the angle between $v$ and $B$ is

The magnetic field at the center of a circular current-carrying loop of radius $R$ is $B_0$. The magnetic field at an axial point at a distance $x = R$ from the center of the loop is:

There is a ring of radius \( r \) having linear charge density \( \lambda \) and rotating with a uniform angular velocity \( \omega \). The magnitude of the magnetic field produced by this ring at its own centre would be (\( \mu_0 \)= permeability of air)

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

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 \( \frac{1}{27}\text{th} \) of its value at the centre of the coil is

The current through a circular coil is halved and the radius of the coil is doubled. If $B_1$ and $B_2$ are respectively the initial and final magnetic field strengths at the center of the coil, then:

An electric field of $8 \times 10^{4}\text{ V m}^{-1}$ and a magnetic field of $6 \times 10^{-3}\text{ T}$ are applied simultaneously on an electron beam such that the path of the beam remains undeviated. Then the speed of the electron will be:

A circular coil of radius $r = 10\text{ cm}$ having $300$ turns carries a current of $2\text{ A}$. The coil is suspended vertically in a uniform magnetic field of strength $7\text{ T}$. If the plane of the coil makes an angle of $30^\circ$ with the magnetic field, the torque needed to prevent it from turning is:

The direction of magnetic lines of force inside the solenoid is from \dots

Choose correct option regarding magnetic lines of force.

The magnetic field around a current-carrying solenoid is similar to the magnetic field of a:

The SI unit of magnetic flux density (B) is:

What happens to the magnetic field at the center of a circular coil if the number of turns is doubled while keeping the current constant?

Biot-Savart law indicates that an electron moving with a velocity \( \vec{V} \) produces a magnetic field \( \vec{B} \) around it such that

A proton, an electron and an \(\alpha\)-particle enter at right angles to a uniform magnetic field with the same velocity. If R\(_p\), R\(_e\) and R\(_\alpha\) are the radii of circular paths of these particles, then

The current that has to pass through a single circular loop of radius 10 cm to produce a magnetic field of \(\mu_0\) tesla at its centre is