Magnetic effect of current practice · Mixed difficulty

In order to increase the sensitivity of galvanometer

Consider the following statements regarding a charged particle in a magnetic field

(i) starting with zero velocity, it accelerates in a direction perpendicular to the magnetic field.

(ii) while deflecting in the magnetic field, its energy gradually increases.

(iii) only the component of magnetic field perpendicular to the direction of motion of the charged particle is effective in deflecting it.

(iv) direction of deflecting force on the moving charged particle is perpendicular to its velocity.
Amongst these statements,

A double ionized ${He}^{2+}$ atom travels at right angle to a magnetic field of induction $0.4 \mathrm{~T}$ at a velocity of $10^5 \mathrm{~m} / \mathrm{s}$ describing a circle of radius ' $r$ '. A proton travelling with same speed in the same direction in the same field will describe a circle of radius

The source of magnetic field is ____ & source
of electric field is _____.

The mass of a proton is 1847 times that of an electron. An
electron and a proton are injected into a uniform electric field at
right angle to the direction of the field with the same initial K.E.

The magnetic dipole moment of current loop is independent of

The force acting per unit length on one conductor due to the other for two long parallel current carrying wires is

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

A galvanometer having a resistance of 8 ohm is shunted by a wire of resistance 2 ohm. If the total current is 1 ampere. The part of it passing through the shunt will be

A long hollow tube is carrying an electric current along its length distributed uniformly over its surface. The magnetic field

A charge q moves with velocity ${ }^{\prime} \vec{V}{ }^{\prime}$ through electric field $(\overrightarrow{\mathbf{E}})$ as well as magnetic field $(\overrightarrow{\mathbf{B}})$. Then the force acting on it is

For toroid of mean radius 20 cm, number of turns 240 and a current of 2A. What is the value of magnetic field within toroid?

Assertion (A) : A charged particle is moving in a circle with constant speed in uniform magnetic field. If we increase the speed of particle to twice, its acceleration will become four times.

Reason (R) : In circular path of radius $R$ with constant speed $v$, acceleration is given by $\frac{v^2}{R}$.

A cyclotron in which protons are accelerated has a flux density 1.57 T. The variation of frequency of electric field is $\left[ {{\text{in }}{H_2}} \right]$

If 0.1 m long conductor carrying a current of 50 A is perpendicular to a magnetic field of 1.25 mT. The mechanical power to move the conductor with a speed of $1\,m{s^{ - 1}}$ is

Assertion: Cyclotron does not accelerate electron.

Reason: Mass of the electron is very small.

A magnetic field can be produced by :-

A galvanometer acting as a voltmeter should have

Assertion (A): Magnetic field interacts with a moving charge and not with a stationary charge.

Reason (R): Magnetic field will be produced by a moving charge but not by a stationary charge.

In which of the following case no force exerted
by a magnetic field on a charge ?

Assertion: If the current in a solenoid is
reversed in direction while keeping the same
magnitude, the magnetic field energy stored in the
solenoid decreases.
Reason: Magnetic field energy density is
proportional to square of current

Two long straight conductors carry currents $4A$ and $2A$ into the plane of paper. A circular path is imagined to be enclosing these currents. The value of $\oint {\overline B .\overline {dl} }$ is.

In a cyclotron, if the frequency of proton is $5MHz$, the magnetic field necessary for resonance is

A water drop of mass $3.2 \times {10^{ - 18}}kg$ and carrying a charge of $1.6 \times {10^{ - 19}}C$ is suspended stationary between two plates of an electric field. Given $g = 10m/{s^2}$ , the intensity of the electric field required is

A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity, then

A galvanometer can be converted into an ammeter by using

Assertion: Magnetic moment of toroid is zero.
Reason: Magnetic field outside the volume of current carrying toroid is zero.

As shown in figure a square loop made from a uniform wire. Calculate the magnetic field at the centre of the square if a battery source is connected between the points 'A' & 'C'.

A charged particle moves undeflected in a region of crossed electric and magnetic fields. If the electric field is switched off, the particle has an initial acceleration a. If the magnetic field is switched off, instead of the electric field, the particle will have an initial acceleration

An electron of mass $m$ and charge $q$ is accelerated from rest in a uniform electric field of strength $E$. The velocity acquired by it as it travels a distance $l$ is