Q. No.
What is the dimensional formula of magnetic flux?
1. \(\left[ M L^2 T^{-2}A^{-1}\right]\)
2. \(\left[ M L^1 T^{-1}A^{-2}\right]\)
3. \(\left[ M L^2 T^{-3}A^{-1}\right]\)
4. \(\left[ M L^{-2} T^{-2}A^{-2}\right]\)
1. \(\left[ M L^2 T^{-2}A^{-1}\right]\)
2. \(\left[ M L^1 T^{-1}A^{-2}\right]\)
3. \(\left[ M L^2 T^{-3}A^{-1}\right]\)
4. \(\left[ M L^{-2} T^{-2}A^{-2}\right]\)
A cylindrical magnet is kept along the axis of a circular coil. On rotating the magnet about its axis, the coil will have induced in it:
| 1. | No current |
| 2. | A current |
| 3. | Only an emf |
| 4. | Both an emf and a current |
The magnetic flux through a coil varies with time \(t\) as shown in the diagram. Which graph best represents the variation of the emf \(E\) induced in the coil with time \(t\)?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
A bar magnet is made to fall through a long surface copper tube. The speed \((v)\) of the magnet as a function of time \((t)\) is best represented by:
| 1. | \(a\) | 2. | \(b\) |
| 3. | \(c\) | 4. | \(d\) |
When a conducting wire \(XY\) is moved towards the right, a current flows in the anti-clockwise direction. Direction of magnetic field at point \(O\) is:
| 1. | parallel to the motion of wire. |
| 2. | along with \(XY\). |
| 3. | perpendicular outside the paper. |
| 4. | perpendicular inside the paper. |
| 1. | A metal block is kept in a changing magnetic field. |
| 2. | A metal block is kept in a uniform magnetic field. |
| 3. | A coil is kept in a uniform magnetic field. |
| 4. | Current is passed in a coil. |
1. \(\frac{B^{2} AL}{2\mu_{0}^{2}}\)
2. \(\frac{AL}{2 \mu_{0}}\)
3. \(\frac{1}{2} \mu_{0} B^{2} AL\)
4. \(\frac{B^{2} AL}{2 \mu_{0}}\)
An inductor is connected to a direct voltage source through a switch. Then:
| 1. | a very large emf is induced in inductor when the switch is closed. |
| 2. | a large emf is induced when the switch is opened. |
| 3. | a large emf is induced whether the switch is closed or opened. |
| 4. | no emf is induced whether the switch is closed or opened. |
A long solenoid has self-inductance \(L\). If its length is doubled keeping total number of turns constant, then its new self-inductance will be:
1. \(\frac{L}{2}\)
2. \(2L\)
3. \(L\)
4. \(\frac{L}{4}\)
With the decrease of current in the primary coil from \(2\) A to zero in \(0.01\) s, the emf generated in the secondary coil is \(1000~\text{V}\). The mutual inductance of the two coils is:
1. \(1.25\) H
2. \(2.50\) H
3. \(5.00\) H
4. \(10.00\) H
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