Magnetic effect of current practice · Medium

When a proton has a velocity $\vec{v}=(2 \hat{i}+3 \hat{j}) \times 10^6 \mathrm{~ms}^{-1}$, it experiences a force $\vec{F}=-\left(1.28 \times 10^{-13} \hat{k}\right) \mathrm{N}$. When its velocity is along the $z$-axis, it experiences a force along the $x$-axis. What is the magnetic field?

Statement I - A bar magnet can exert torque on itself due to it's own field.

Statement II - One element of a current carrying wire can exert a force on another element of same wire.

A current of $4 \mathrm{~A}$ produces a deflection of $30^{\circ}$ in the galvanometer. The figure of merit is

A magnetic field can be produced by :-

A proton carrying 1 MeV kinetic energy is moving
in a circular path of radius $R$ in uniform magnetic
field. What should be the energy of an a-particle
to describe a circle of the same radius in the same
field?

Assertion (A) : A charged particle moves along positive $y$-axis with constant velocity in uniform electric and magnetic fields. If magnetic field is acting along positive $x$-axis, then electric field should act along positive $z$-axis.

Reason (R) : To keep the charged particle undeviated the relation $\mathbf{E}=\mathbf{B} \times \mathbf{v}$ must hold good.

In a moving coil galvanometer, we use a radial magnetic feild so that the galvanometer scale is

To which of the following quantities, the radius
of the circular path of a charged particle
moving at right angles to a uniform magnetic
field is directly proportional?

Two galvanometers ' $G_1$ ' and ' $G_2$ ' require $2 \mathrm{~mA}$ and $3 \mathrm{~mA}$ respectively to produce the same deflection. Then

A charged particle moves through a magnetic field perpendicular to its direction, then

A magnetic dipole is placed under the effect of two magnetic fields inclined at $75^{\circ}$ to each other. One of the field has a magnetic induction of $1.5 \times 10^{-2} \mathrm{~T}$. The magnet comes to rest at an angle of $30^{\circ}$ with the direction of this field. The magnitude of the other field is

A charge particle moving in magnetic field $B$, has the components of velocity along $B$ as well as perpendicular to $B$. The path of the charge particle will be

Identify the correct statement from the following

A long solenoid of length L has a mean
diameter D. It has n layers of windings of N
turns each. If it carries a current I, the
magnetic field at its centre will be

Cyclotron is a device which is used to:

Assertion: Magnetic force between two charges is generally much smaller than the electric force between them.
Reason: Speeds of charges are much smaller than the free–space speed of light.

A proton enters into a magnetic field of induction $1.732 \mathrm{~T}$, with a velocity of $10^7 \mathrm{~m} / \mathrm{s}$ at an angle $60^{\circ}$ to the field. The force acting on the proton is $\left(\mathrm{e}=1.6 \times 10^{-19} \mathrm{C}, \sin 60^{\circ}=\cos 30^{\circ}=\right.$ $\frac{\sqrt{3}}{2}$ )

A long straight wire carries a current $15 \mathrm{~A}$. Calculate the magnetising field $\mathrm{H}$ at a point at distance $0.105 \mathrm{~m}$ from the axis of wire

A circular coil carrying a certain current produces a magnetic field $B_0$ at its centre. The coil is now rewound so as to have 4 turns and the same current is passed through it. The new magnetic field at the centre is

Statement-I: If by mistake a voltmeter is connected in series it gets burnt
Statement-II: Current will drastically decrease in the circuit.

The turns of a solenoid, designed to provide a given magnetic
flux density along its axis, are wound to fill the space between
two concentric cylinders of fixed radii. How should the diameter
$d$ of the wire used be chosen so as to minimize the heat
dissipated in the windings?

Fleming's left and right hand rules are used in:

The magnetic induction at the centre of a current carrying circle of radius $r$, is

A charge of $3.14 \times 10^{-6} \mathrm{C}$ is distributed uniformly over a circular ring of radius $20.0 \mathrm{~cm}$. The ring rotates about its axis with an angular velocity of $60.0\, \mathrm{rad}\, \mathrm{s}^{-1}$. Find the ratio of the electric field to the magnetic field at a point on the axis at a distance of $5.00 \mathrm{~cm}$ from the centre.

Two parallel wires are carrying electric currents of equal magnitude and in the same direction. They exert:

A solenoid $60 \mathrm{~cm}$ long and of radius $4.0 \mathrm{~cm}$ has 3 layers of windings of 300 turns each. A $2.0 \mathrm{~cm}$ long wire of mass $2.5 \mathrm{~g}$ lies inside the solenoid near its centre normal to its axis; both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of $6.0 \mathrm{~A}$ in the wire. What value of current in the windings of the solenoid can support the weight of the wire ? $g=9.8 \mathrm{~ms}^{-2}$.

An electron having charge ' $e$ ' is moving with a constant speed $v$ along a circle of radius $r$. Its magnetic moment will be

A 0.8 m long solenoid has 800 turns and has a field density of $2.52\mathrm{ } \times \mathrm{ }{10^{ - 3}}T$ at its centre. What is current in the wire ?

A galvanometer of resistance $25\,\,\mathrm{\Omega }$ giving full scale deflection for a current of $10\,\,milli\,\,ampere$, is to be changed into a voltmeter of range $100\,\,V$ by connecting a resistance of $'R'$ in series with galvanometer. The value of resistance $R$ in $\mathrm{\Omega }$ is

A galvanometer has resistance 500 ohm. It is shunted so that its sensitivity decreases by 100 times. Find the shunt resistance.