What is the result of an electric charge in uniform motion?
1. | an electric field only. |
2. | a magnetic field only. |
3. | both electric and magnetic field. |
4. | neither electric nor magnetic field. |
The dots in the figure depict a magnetic field that is perpendicular to the plane of the paper and emanates from it. The trajectory of a particle in the plane of the paper is depicted by the curve \(ABC\). What exactly is the particle?
1. | Proton. | 2. | Electron. |
3. | Neutron. | 4. | It cannot be predicted. |
1. | the speed will change. |
2. | the direction will change. |
3. | both (1) and (2) |
4. | none of the above |
A particle of charge \(+q\) and mass \(m\) moving under the influence of a uniform electric field \(E\hat i\) and a uniform magnetic field \(\mathrm B\hat k\) follows a trajectory from \(P\) to \(Q\) as shown in the figure. The velocities at \(P\) and \(Q\) are \(v\hat i\) and \(-2v\hat j\) respectively. Which of the following statement(s) is/are correct?
1. | \(E=\frac{3}{4} \frac{{mv}^2}{{qa}}\). |
2. | Rate of work done by electric field at \(P\) is \(\frac{3}{4} \frac{{mv}^3}{a}\). |
3. | Rate of work done by both fields at \(Q\) is zero. |
4. | All of the above. |
1. | \(\frac{M a_0}{e} ~\text{west,}~ \frac{M a_0}{e v_0}~\text{up}\) |
2. | \(\frac{M a_0}{e} ~\text {west,} ~\frac{2 M a_0}{e v_0}~\text{down}\) |
3. | \(\frac{M a_0}{e} ~\text{east,} \frac{2 M a_0}{e v_0}~\text{up}\) |
4. | \(\frac{M a_0}{e} ~\text {east,} \frac{3 M a_0}{e v_0} ~\text {down}\) |
When a positively charged particle moves in an \(x\text-y\) plane, its path abruptly changes due to the presence of electric and/or magnetic fields beyond \(P\). The curved path is depicted in the \(x\text-y\) plane and is discovered to be noncircular. Which of the following combinations is true?
1. \(\vec{{E}}=0 ; \vec{{B}}={b} \hat{i}+{c} \hat{k}\)
2. \(\vec{E}={a\hat{i}} ; \vec{B}={c} \hat{k}+a\hat{i}\)
3. \(\vec{E}=0 ; \vec{B}=c \hat{j}+b \hat{k}\)
4. \(\vec{E}=a\hat i ; \vec{B}=c\hat{k}+{b}\hat{j}\)
A charged particle is projected through a region in a gravity-free space. If it passes through the region with constant speed, then the region may have:
1. \(\vec{E}=0, \vec{B} \neq 0\)
2. \(\vec{E} \neq 0, \vec{B} \neq 0\)
3. \(\vec{E} \neq 0, \vec{B}=0\)
4. Both (1) & (2)
1. | \(8\) N in \(-z\text-\)direction. |
2. | \(4\) N in the \(z\text-\)direction. |
3. | \(8\) N in the \(y\text-\)direction. |
4. | \(8\) N in the \(z\text-\)direction. |
1. | Angle between \(\vec v\) and \(\vec {B}\) is necessarily \(90^{\circ}\). |
2. | Angle between \(\vec v\) and \(\vec {B}\) can have any value other than \(90^{\circ}\). |
3. | Angle between \(\vec v\) and \(\vec {B}\) can have any value other than zero and \(180^{\circ}\). |
4. | Angle between \(\vec v\) and \(\vec {B}\) is either zero or \(180^{\circ}\). |
A current-carrying wire is placed in a uniform magnetic field in the shape of the curve \(y= \alpha \sin \left({\pi x \over L}\right),~0 \le x \le2L.\)
What will be the force acting on the wire?
1. | \(iBL \over \pi\) | 2. | \(iBL \pi\) |
3. | \(2iBL \) | 4. | zero |