1. | collapse |
2. | stretch out further |
3. | neither, the magnetic field is zero outside a solenoid |
4. | the answer depends on the direction of the current |
(I) | \(A,B\) | at two adjacent vertices
(II) | \(A,C\) at the ends of a diagonal. | at two points
1. | \(2\) | 2. | \(\dfrac12\) |
3. | \(\dfrac{1}{\sqrt2}\) | 4. | \(1\) |
A wire carrying a current \(I_0\) oriented along the vector \(\big(3\hat{i}+4\hat{j}\big)\) experiences a force per unit length of \(\big(4F\hat{i}-3F\hat{j}-F\hat{k}\big).\) The magnetic field \(\vec{ B}\) equals:
1. \(\dfrac{F}{I_0}\left(\hat{i}+\hat{j}\right)\)
2. \(\dfrac{5F}{I_0}\left(\hat{i}+\hat{j}+\hat{k}\right)\)
3. \(\dfrac{F}{I_0}\left(\hat{i}+\hat{j}+\hat{k}\right)\)
4. \(\dfrac{5F}{I_0}\hat{k}\)
To ensure that the magnetic field is radial in a moving coil galvanometer:
1. | The number of turns in the coil is increased. |
2. | The magnet is taken in the form of a horse-shoe. |
3. | The poles are cut cylindrically. |
4. | The coil is wound on an aluminum frame. |
1. | \(q\Phi\) | 2. | \(\dfrac{q\Phi}{2\pi}\) |
3. | \(\pi q\Phi\) | 4. | \(\dfrac{q\Phi}{\pi}\) |
Given below are two statements:
Statement I: | \({d\vec l}\) of a current-carrying wire carrying a current, \(I\) is given by: \({d\vec B}=\dfrac{\mu_0}{4\pi}~I\left({d\vec l}\times\dfrac{\vec r}{r^3}\right ),\) where \(\vec{r}\) is the position vector of the field point with respect to the wire segment. |
The magnetic field due to a segment
Statement II: | The magnetic field of a current-carrying wire is never parallel to the wire. |
1. | Statement I and Statement II are True and Statement I is the correct explanation of Statement II. |
2. | Statement I and Statement II are True and Statement I is not the correct explanation of Statement II. |
3. | Statement I is True, and Statement II is False. |
4. | Statement I is False, and Statement II is True. |
1. | attract each other. |
2. | repel each other. |
3. | exert no force on each other, but exert a torque. |
4. | neither exert any force nor any torque on each other. |
1. | a force along \(+y\) axis only. |
2. | a force along \(-y\) axis. |
3. | zero force, but a torque. |
4. | no force and no torque. |
A metal rod \(PQ\) (carrying current from \(P\) to \(Q\)) is placed perpendicular to an infinitely long wire carrying a current \(i_0.\) If this arrangement lies in a horizontal plane, in which direction will the rod \(PQ\) rotate?
1. | zero | 2. | \(2\pi r i B\) |
3. | \(\pi r^2i B\) | 4. | \(2\pi r^2i B\) |