Force On A Moving Charge In Magnetic Field - Practice Questions & MCQ

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 particle of mass M and charge Q moving with velocity $\vec{v}$ describes a circular path of radius $R$ when subjected to a uniform transverse magnetic field B. The work done by the field when the particle completes one full circle is

A negative test charge is moving near a long straight wire carrying a current.  The force acting on the test charge is parallel to the direction of the current.  The motion of the charge is :

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a

At a specific instant, the emission of the radioactive compound is deflected in a magnetic field. The compound can emit

The emission at the instant can be

In a certain region, static electric and magnetic fields exist. The magnetic field is given by $\overrightarrow{\mathrm{B}}=\mathrm{B}_0(\hat{i}+2 \hat{j}-4 \hat{k})$. If a test charge moving with a velocity $\vec{v}=v_0(3 \hat{i}-\hat{j}+2 \hat{k})$ experiences no force in that region, then the electric field in the region, in SI units, is :

Direction :  In the following question, a statement of Assertion (A)  is followed by a statement of reason (R). Mark the correct choice as: 

Assertion : Workdone by magnetic field on a moving change is zero.

Reason :  Force experienced by moving charge in a magnetic field may be zero.