Magnetic effect of current practice · Mixed difficulty

The direction of magnetic field $d \vec{B}$ due to a current element $\mathrm{I} d \vec{l}$ at a point of distance $r$ from it, when a current I passes through a long conductor is in the direction

A charged particle moving along $+{x}$ direction with velocity ${v}$ enters a region where there is a uniform magnetic field $\vec{B}=-B \hat{k}$ from $x=0$ to $x=d$, the particle gets deflected at an angle $\theta$ from its intial path. The specific charge of the particle is :

An electron of mass m and charge q is travelling with a speed v along a circular path of radius r at right angles to a uniform magnetic filed B. If speed of the electron is double and the magnetic field is halved, then resulting path would have a radius of

Assertion: The energy of charged particle moving in a uniform magnetic field does not change.

Reason: Work done by magnetic field on the charge is zero.

A solenoid of length 0.4 m and having 500 turns of wire carries a current of 3 A. A thin coil having 10 turns of wire and of radius 0.01 m carries of 0.4 A. Assuming long solenoid, magnetic field at the centre of the solenoid is

The condition under which a point charge moving through a magnetic field, experiences maximum force (in terms of magnitude) is

Before using the tangent galvanometer, its coil
is set up in

Two identical current carrying coaxial loops, carry current $i$ in an opposite sense. A simple amperian loop passes through both of them once. Calling the loop as $C$,

A proton moving with a velocity of $\mathrm{2} \times {10^6}\,\mathrm{m}{\mathrm{s}^{ - 1}}$ describes a circle of radius $R$ in a magnetic field. The speed of an $\alpha -$ particle to describe a circle of same radius in the same magnetic field is

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

A charged particle is fired at an angle $\theta$ to a uniform magnetic field directed along the $\mathrm{X}$-axis. During its motion, the pitch of the helical path is equal to the maximum distance of the particle from the $\mathrm{X}$-axis, then

There are three voltmeters of the same range but of resistances $10000\,\,\mathrm{\Omega },\,\,8000\,\,\mathrm{\Omega }$ and $4000\,\,\mathrm{\Omega }$ respectively. The best voltmeter among these is the one whose resistance is

If the number of turns per unit length of a coil of a solenoid is doubled, the self inductance of the solenoid will

A constant voltage is applied to a series $\mathrm{R}-\mathrm{L}$ circuit by closing the switch. The voltage across inductor $(\mathrm{L}=2 \mathrm{H})$ is $20 \mathrm{~V}$ at $\mathrm{t}=0$ and drops to $5 \mathrm{~V}$ at $20 \mathrm{~ms}$. The value of $\mathrm{R}$ in $\Omega$ is:

A magnet is suspended lengthwise from a spring and while it oscillates, the magnet moves in and out of the coil C connected to a galvanometer G. Then as the magnet oscillates.

A cylindrical conductor of radius ‘R’ carries a current ‘i’. The value of magnetic field at a point which is R/4 distance inside from the surface is 10 T. Find the value of magnetic field at point which is 4R distance outside from the surface

A charge q is spread uniformly over an insulated loop of radius r. If it is rotated with an angular velocity $\omega$ with respect to normal axis then the magnetic moment of the loop is

A winding wire which is used to frame a solenoid can bear a maximum $10 \mathrm{~A}$ current. If length of solenoid is $80 \mathrm{~cm}$ and it's cross sectional radius is $3 \mathrm{~cm}$ then required length of winding wire is $(\mathrm{B}=0.2 \mathrm{~T})$ :-

A milli volt meter of 25 milli volt range is to be converted into an ammeter of 25 ampere range. The value of necessary shunt will be.

To decrease the range of an ammeter, its resistance need to be increased. An ammeter has resistance ${R_0}$ and range $I$. Which of the following resistance can be connected in series with it to decreases its range to $I/n$?

An electric bulb is rated as 200 W. What will be the peak magnetic field at 4 m distance produced by the radiations coming from this bulb? Consider this bulb as a point source with 3.5% efficiency.

A proton and an $\alpha -$ particle enter a uniform magnetic field perpendicularly with the same speed. If proton takes $25\,\mu$ second to make 5 revolutions, then the time period for the $\alpha -$ particle would be

Select the incorrect statement about Lorentz Force.

A charge $Q$ is moving $dl$ distance in the magnetic field $B$.find the value of work done by $B$.

A long solenoid of radius 1 mm has 100 turns per mm. If 1 A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:

A proton is accelerated in a cyclotron where the applied magnetic field is $0.5 {~T}$. If the potential gap is $10 \,{kV}$, then how much revolutions the proton has to make between the dee's to acquire a kinetic energy of $12 \,{MeV}$ ?

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

10 A current is passing through a very long wire of radius $5 \mathrm{~cm}$. Then magnetic field at a distance of $\mathbf{2} \mathbf{~ c m}$ inside from its curved surface is$\_\_\_\_\_\_\_$ $\times 10^{-5} \mathrm{~T}$

A conducting circular loop of radius $r$ carries a constant current $i$. It is placed in uniform magnetic field $\vec{B}$, such that $\vec{B}$ is perpendicular to plane of the loop. Find the magnetic force acting on the loop.

Force on current carrying loop (Radius $=R$) in uniform magnetic $(B)$ field which is at an angle $30^{\circ}$ with the normal will be: