Single Choice

If a charged particle at rest experiences no electromagnetic force,

Athe electric field must be zero
Correct Answer
Bthe magnetic field must be zero
Cthe electric field may or may not be zero
Dthe magnetic field may or may not be zero

Solution


SIMILAR QUESTIONS

Magnetism

A particle having a mass of $$10^{-2}$$ kg carries a charge of $$5 \times 10^{-8}$$ C. The particle is given an initial horizontal velocity of $$10^5 ms^{-1}$$ in the presence of electric field $$\overset{\rightarrow}{E}$$ and magnetic field $$\overset{\rightarrow}{B}$$. To keep the particle moving in a horizontal direction, it is necessary that (i) $$\overset{\rightarrow}{B}$$ should be perpendicular to the direction of velocity and $$\overset{\rightarrow}{E}$$ should be along the direction of velocity. (ii) Both $$\overset{\rightarrow}{B}$$ and $$\overset{\rightarrow}{E}$$ should be along the direction of velocity. (iii) Both $$\overset{\rightarrow}{B}$$ and $$\overset{\rightarrow}{E}$$ are mutually perpendicular and perpendicular to the direction of velocity. (iv) $$\overset{\rightarrow}{B}$$ should be along the direction of velocity and $$\overset{\rightarrow}{E}$$ should be perpendicular to the direction of velocity. Which one of the following pairs of statements is possible

Magnetism

When a proton is released from the rest in a room, it starts with an initial acceleration $$a_{0}$$ towards north with a speed $$v_{0}$$ it moves with an initial acceleration $$3a_{0}$$ towards west. The electric and magnetic fields in the room are

Magnetism

Consider the motion of a positive point charge in a region where there are simultaneous uniform electric and magnetic fields $$\overrightarrow{E} = E_{0}\hat{j}$$ and $$\overrightarrow{B} = B_{0}\hat{j}$$. At time t = 0, this charge has velocity $$\overrightarrow{v}$$ in the x-y plane, making an angle $$\theta$$ with the x axis. Which of the following option(s) is(are) correct for time t > 0 ?

Magnetism

A closed coil having $$100$$ turns is rotated in a uniform magnetic field $$B=4.0\times { 10 }^{ -4 }T$$ about a diameter whcih is perpendicular to the field. The angular velocity of rotation is $$300$$ revolutions per minute. The area of the coil is $$25{cm}^{2}$$ and its resistance is $$4.0\Omega$$. Find (a) the average emf developed in half turn from a position where the coil is perpendicular to the magnetic field, (b) the average emf in a full turn and (c) the net charge displaced in part (a)

Magnetism

A charged particle moves in a gravity-free space without change in velocity. Which of the following is/are possible?

Magnetism

A charged particle moves along a circle under the action of possible constant electric and magnetic fields. Which of the following are possible?

Magnetism

A charged particle goes undeflected in a region containing electric and magnetic fields. It is possible that

Magnetism

If a charged particle goes unaccelerated in a region containing electric and magnetic fields,

Magnetism

Let $$\vec E$$ and $$\vec B$$ denote electric and magnetic fields in a frame S and $$\vec E'$$ and $$\vec B'$$ in another frame S' moving with respect to S at a velocity $$\vec v$$. Two of the following equations are wrong. Identify them:

Magnetism

When a proton is released from rest in room, it starts with an initial acceleration $${ a }_{ 0 }$$ towards west When it is projected towards north with a speed $${ V }_{ 0 }$$ it moves with an initial acceleration $${ 3a }_{ 0 }$$ towards west. The electric and magnetic fields in the room are :

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