Magnetic effect of current practice · Mixed difficulty

A long straight wire carries a current of $20 \mathrm{~A}$. The maximum force experienced by an electron moving at a speed of $100 \mathrm{~km} / \mathrm{s}$, at a distance of $6.4 \mathrm{~cm}$ from the wire is

A wire of length $l$ is bent in the form of a circular loop and is suspended in a region of a uniform magnetic field $B$. When a steady current $I$ is passed through the loop, the maximum torque experienced by it is

In a watch glass, water is taken and it is kept in
a non-uniform magnetic field. Water moves
from strong field to weak field. The magnetic
effect observed is

Assertion (A): No net force acts on a rectangular coil carrying a steady current when suspended freely in a uniform magnetic field.

Reason (R): Forces acting on each pair of the opposite sides of the coil are equal and opposite.

The work done by a magnetic field, on a moving charge is

A current carrying loop lies on a smooth horizontal plane. Then,

When a current carrying conductor is placed in magnetic field,then:

Two charges of equal magnitude and at a distance r exert a force F on each other. If the charges are halved and distance b/w them is doubled, then the new force acting on each charge is.

A straight wire of diameter $0.5 \mathrm{~mm}$ carrying a current of $1 \mathrm{~A}$ is replaced by another wire of $1 \mathrm{~mm}$ diameter carrying the same current. The strength of the magnetic field far away is

A galvanmeter has a coil of resistance $200 \Omega$ with a full scale deflection at $20 \mu \mathrm{A}$. The value of resistance to be added to use it as an ammeter of range $(0-20) \mathrm{mA}$ is:

An infinite hollow cylindrical of radius $R$ having uniform surface charge density $\sigma$ is rotated with constant angular velocity $\omega$ about its axis. Magnetic field at the centre of cylinder is $B=\mu_0 \sigma R^x \omega.$ Find $x.$

Statement-1: Net force on a current carrying loop in a non-uniform magnetic field must be non-zero.
Statement-2: Force on a current carrying wire of length $\vec{dl}$ placed in magnetic field $\overrightarrow{{B}}$ is given by $\overrightarrow{d {F}}=i \vec{dl} \times \overrightarrow{{B}}$

If a shunt of $15\,\,\Omega$ is connected with a galvanometer of resistance $60\,\,\Omega$, then the resistance necessary to be connected in series with circuit for keeping the main current constant.

A charge particle having charge 2C is thrown with velocity of $\left( {2\hat i + 3\hat j} \right)\,m/s$ inside a region having $\overrightarrow E = - 2\hat j\,N/C$ and magnetic field 5KT. The Lorentz force acting on particle is

A charge particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the charge particle increases to 4 times its initial value. What will be the ratio of new radius to the original radius of circular path of the charge particle

A toroid having average diameter $2.5 \mathrm{~m}$, number of turns 400, current $=2 \mathrm{~A}$ and magnetic field $=10 \mathrm{~T}$ what will be induced magnetic field? (in $\mathrm{amp/m}$)

There exists a uniform and constant magnetic field $B=1.67 T$ along positive $z$-axis. Simultaneously a proton and an alpha particle are projected from the origin with same speed $v=4 \sqrt{5} \times 10^5 \mathrm{~ms}^{-1}$ along positive and negative $x$-axis respectively. Find the separation between them when their velocities become mutually perpendicular for the first time. Ignore the force of interaction between them as well as any force other than magnetic force. Mass of the proton is $1.67 \times 10^{-27} \mathrm{~kg}$.

The angular momentum of the electron is J. If e – charge of electron, $m =$ mass of electron, then its magnetic moment will be.

Two parallel wires carrying currents in
opposite directions

Assertion (A): In M.C.G, the deflection '$\theta$' is directly proportional to the strength of the current.

Reason (R): In M.C.G., the the torque experienced by the loop is $\mathrm {BiAN}\cos\theta$

Assertion: Resistance of an ammeter is less than the resistance of a milli ammeter.

Reason: Value of shunt required in case of ammeter is more than a milli ammeter.

The sensitivity of a tangent galvanometer is increased if

The force acting on a current carrying wire joining two fixed points $\mathrm{A}$ and $\mathrm{B}$ in a uniform magnetic field

A tangent galvanometer has a coil with 50 turns and radius equal to $4\;cm$. A current of $0.1\;A$ is passing through it. The plane of the coil is set parallel to the earth’s magnetic meridian. If the value of the earth’s horizontal component of the magnetic field is $7 \times {10^{ - 5}}tesla$ tesla and ${\mu _0} = 4\pi \times {10^{ - 7}}weber/amp \times m$, then the deflection in the galvanometer needle will be

Two circular coils A and B with their centers lying on the same number of turns and cary equal currents in the same sense. They are separated by a distance, have different diameters but subtend same angle at a point $\mathrm{P}$ lying on their common axis. The coil B lies exactly midway between coil $\mathrm{A}$ and the point $\mathrm{P}$. The magnetic field at point $\mathrm{P}$ due to coils $A$ and $B$ is $B_1$ and $B_2$ respectively

Two particles $X$ and $Y$ having equal charges are being accelerated through the same potential difference. Thereafter they enter normally in a region of uniform magnetic field and describes circular paths of radii $R_1$ and $R_2$ respectively. The mass ratio of $X$ and $Y$ is :

Two parallel beam of positrons moving in the
same direction will

A solenoid of length 1.5 m and 4 cm diameter possesses 10 turns per cm. A current of 5A is flowing through it, the magnetic induction at axis inside the solenoid is
$\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,\,\mathrm{weber}\,\,am{p^{ - 1}}\,{m^{ - 1}}} \right)$

A galvanometer has a coil of resistance $20\mathrm{ }\Omega$ and its full scale deflection current is 9 A. Value of shunt resistance that should be connected with it so that it can read a maximum of 99 A current, is

An electron is released from the origin at a place where a uniform electric field $\vec{E}$ and uniform magnetic field $\overrightarrow{\mathrm{B}}$ exists along the negative $\mathrm{y}$-axis and negative $z$-axis respectively. Then which of the following are INCORRECT.