Magnetic effect of current practice · Mixed difficulty

When the number of turns of the coil is
doubled, the current sensitivity of a moving coil
galvanometer is doubled whereas the voltage
sensitivity of the galvanometer

A charged dust particle of radius $5 \times {10^{ - 7}}$m is located in a horizontal electric field having an intensity of $6.28 \times {10^5}\;\mathrm{V}{\mathrm{m}^{ - 1}}$. The surrounding medium in air with coefficient of viscosity $\mathrm{\eta } = 1.6 \times {10^{ - 15}}\mathrm{Ns}{\mathrm{m}^{ - 2}}.$ If this particle moves with a uniform horizontal speed of 0.01 $\mathrm{m}{\mathrm{s}^{ - 1}},$ the number of electrons on it will be

The magnitude of magnetic field at two points on the axis of a circular coil at distances of 0.05 m and 0.2 m from its centre are in the ratio $8: 1.$ The radius of coil is:

A non-planar closed loop of arbitrary shape carrying a current $I$ is placed in uniform magnetic field. The force acting on the loop

When a charged particle moves perpendicular
to a uniform magnetic field, there is a change in
its:

Statement (A): The restoring couple in the moving coil galvanometer is due to the current in the coil

Statement(B): Wires of magnetic field around a current carrying straight conductor will be circular in a plane parallel to the conductor

Statement(C): When a charged particle enters a uniform magnetic field, its kinetic energy increases

The direction of the force on a current carrying
conductor held perpendicular to a uniform
magnetic field is given by

A galvanometer can be converted into a voltmeter by connecting

Assertion: A linear solenoid carrying current is equivalent to a bar magnet.
Reason: The magnetic field lines due to current carrying solenoid resemble exactly with those of a bar magnet.

In a moving coil galvanometer, to make the
field radial

A solenoid consists of 100 turns of wire and has a length of 10 cm. The magnetic field inside the solenoid when it carries a current of 0.500 A will be

In moving coil galvanometer, strong horse shoe
magnet of concave shaped pole pieces is used to

The two parallel wires carry current in
opposite directions

If an electron of velocity $(2\hat{i} +3\hat{j})$ is subjected to magnetic field of $4\hat{k} ,$ then its

(a) path will change

(b) speed does not change

(c) path must be circular

(d) momentum is constant

A bar magnet is placed inside a uniform
magnetic field. What does it experience?

A closely wound solenoid of length $1 \mathrm{~m}$ has 5 layers of 500 turns each. If the magnitude of magnetic field inside the solenoid near its centre is $4.4 \mathrm{mT}$, the current carried is-

Current $\mathrm{i}$ is carried in a wire of length $\mathrm{L}$. If the wire is turned into a circular coil, the maximum magnitude of torque in a given magnetic field $\mathrm{B}$ will be:

An electron is moving in a circle of radius $r$ in a uniform magnetic field B. Suddenly, the field is reduced to $\frac{B}{2}$. The radius of the circular path now becomes :

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

Assertion (A): The coil is bound over the metallic frame in moving coil galvanometer.
Reason (R): The metallic frame helps in making steady deflection without any oscillations.

A charged particle moves in a circular path in a uniform magnetic field. If its speed is reduced, then its time period will

The materials for the construction of electro magnets should have

An electron moving with velocity $2 \times 10^7 \mathrm{~m} / \mathrm{s}$, describes a circle in a magnetic field of strength $2 \times {10^{ - 2}}T.$ If $\frac{\mathrm{e}}{\mathrm{m}}$ of electron is $1.76 \times 10^{11} \mathrm{C} / \mathrm{kg}$.
Then the diameter of the circle will be

A solenoid of length 22.5 cm has a total of 900 turns and carries a current of 0.8 A. What is the magnetizing field H near the centre and far away from the end of the solenoid?

The magnetic field at the centre of a circular coil of radius $r$, due to current $I$ flowing through it, is $B$. The magnetic field at a point along the axis at a distance $\frac{r}{2}$ from the centre is:

Statement-1 : The sensitivity of a moving coil galvanometer is increased by placing a suitable magnetic material as a core inside the coil.

and
Statement-2 : Soft iron has a high magnetic permeability and cannot be easily magnetized or demagnetized.

A positively charged particle moves in a region having a uniform magnetic field and uniform electric field in same direction. At time $t=0$, the velocity of the particle is perpendicular to the field direction. The subsequent path of the particle will be

A solenoid having 2000 turns per meter has a core of area $4 \mathrm{~cm}^2$ and relative permeability 220. It carries a current of $5 \mathrm{~A}$. The which statement among the following is true?

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

Assertion: A current element is a source of magnetic field.
Reason: A moving charge is a source of magnetic field.