Magnetic effect of current practice · Mixed difficulty

If the angular momentum of an electron is $\vec J\;$ then the magnitude of the magnetic moment will be

Cyclotron is a device which is used to:

Two concentric rings are kept in the same plane. Number of turns in each ring is $\mathbf{2 5}$. Their radii are $50 \mathrm{~cm}$ and $200 \mathrm{~cm}$ and they carry electric currents of $0.1 \mathrm{~A}$ and $0.2 \mathrm{~A}$ respectively, in mutually opposite directions. The magnitude of the magnetic field produced at their centre is $\_\_\_\_\_\_\_$ T.

In a current carrying long solenoid, the field produced does not depend upon

Sensitivity of potentiometer can be increased by

In a moving coil galvanometer, the deflection in the coil is 0.025 rad when a current of 20 mA is passed through it. If the torsional constant of suspension wire is $2 \times 10^{-3} \mathrm{~N}-\mathrm{m} \mathrm{~rad}^{-1},$ magnetic field is $1 \times 10^{-3} \mathrm{~T}$ and the number of turns in the coil is 200, then the area of each turn of coil (in $\mathrm{cm}^2)$ is:

The magnitude of the magnetic field inside a
long solenoid is increased by

In a moving coil galvanometer, the deflection of the coil $\theta$ is related to the elecrical current $i$ by the relation

The formula for magnetic field of a certain component is given by $B=\frac{\mu_0 N i}{2 \pi r}$

Where, $\mathbf{N}=$ total number of turns
$i=$ current through it
${r}=$ radius.

The component is

A current carrying coil is placed in a uniform magnetic field of induction $B$. If the current in the coil is $I$, it has $N$ turns, and $A$ is the face area of the coil and normal to the surface makes an angle $\theta$ with $B$, then the torque experienced by the coil is

A current carrying wire produces in the neighborhood

A long current carrying wire produces a magnetic field of $1 \mathrm{~T}$ at a distance of $\mathrm{r}$. The magnetic field at (A) $\frac{r}{2}$, (B) $2 r$ and (C) $3 r$ is

Statement-1: Two long parallel conductors carrying currents in the same direction experience a force of attraction.
Statement-2: The magnetic produced in the space between the conductors are in the same direction.

A closed loop carrying a current $I$ lies in the $x z$-plane. The loop will experience a force if it is placed in a region occupied by uniform magnetic field along

Assertion: Cyclotron is used to accelerate heavy charged particles, such as proton. It not suitable for accelerating light charged particles, such as electrons.

Reason: Specific charge of proton is more as compared to electron.

A tightly wound 100 turns coil of radius $10 \mathrm{~cm}$ carries a current of $7 \mathrm{~A}.$ The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4 \pi \times 10^{-7}$ SI units):

A coil of insulated wire is connected to a battery. If it is taken to galvanometer, its pointer is deflected, because

A uniform conducting wire of length 12a and resistance $R$ is wound up as a current carrying coil in the shape of,
1) an equilateral triangle of side '$a$' 2) a square of side '$a$'
The magnetic dipole moments of the coil in each case respectively are

Two solenoids are given- 1 st has 1 turn per unit length and 2nd has $n$ turns per unit length. Ratio of magnetic fields at their centers is

A circular loop of radius 0.0157 m carries a current of 2 Amperes. The magnetic field at the centre of the loop is $\left[ {{\mu _ \circ } = 4\pi \times {{10}^{ - 7}}\,\,wb/A - m} \right]\,\left[ {in\,\,wb/{m^2}} \right]$

In a sufficiently long solenoid, the magnetic field at centre of its length (on axial point) is ${B}_1$ and is ${B}_2$ near the end of solenoid (on axial point). Find $B_1 / B_2$.

A current of $\left( {\frac{2}{3}} \right)\,A$ produces a deflection of $\mathrm{6}{\mathrm{0}^0}$ in a tangent galvanometer. The reduction factor is

With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is

(A) Directly proportional to the length of the potentiometer wire

(B) Directly proportional to the potential gradient of the wire

(C) inversely proportional to the potential gradient of the wire

(D) inversely proportional to the length of the potentiometer wire

Choose the correct option for the above statements:

Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is

The law which states that ‘a variation in an
electric field causes magnetic field, is

Lorentz force can be calculated by using the formula

Consider a long straight conducting wire. The magnetic field is determined as $B$ at a distance of $5 \mathrm{~cm}$ from the wire. The field at $40 \mathrm{~cm}$ from the wire would be

A 0.1 m long conductor carrying a current of 50A is perpendicular to a magnetic field of 1.25 mT. The mechanical power to move the conductor with a speed of 1m/s is

A solenoid has an inductance of $50\, \mathrm{mH}$ and a resistance of $0.025\, \Omega$. If it is connected to a battery, how long will it take for the current to reach one half of its final equilibrium value ?

Assertion (A): If a proton and an $\alpha$-particle enter a uniform magnetic field perpendicularly, with the same speed, the time period of revolution of $\alpha$-particle is double that of proton.

Reason (R): In a magnetic field, the time period of revolution of a charged particle is inversely proportional its specific charge.