1. | \(0\) | 2. | \(2\) weber |
3. | \(0.5\) weber | 4. | \(1\) weber |
In a coil of resistance \(10\) \(\Omega\), the induced current developed by changing magnetic flux through it is shown in the figure as a function of time. The magnitude of change in flux through the coil in Weber is:
1. \(2\)
2. \(6\)
3. \(4\)
4. \(8\)
A coil of resistance \(400~\Omega\) is placed in a magnetic field. The magnetic flux \(\phi~\text{(Wb)}\) linked with the coil varies with time \(t~\text{(s)}\) as \(\phi=50t^{2}+4.\) The current in the coil at \(t=2~\text{s}\) is:
1. \(0.5~\text{A}\)
2. \(0.1~\text{A}\)
3. \(2~\text{A}\)
4. \(1~\text{A}\)
1. | increases continuously. |
2. | decreases continuously. |
3. | first increases and then decreases. |
4. | remains constant throughout. |
1. | \(2~\text{A}\) | 2. | \(0.25~\text{A}\) |
3. | \(1.5~\text{A}\) | 4. | \(1~\text{A}\) |
1. | \(5\) V | 2. | \(0.5\) V |
3. | \(0.05\) V | 4. | \(5\times10^{-4}\) V |
The figure shows planar loops of different shapes moving out of or into a region of a magnetic field which is directed normally to the plane of the loop away from the reader. Then:
1. | for the rectangular loop abcd, the induced current is clockwise. |
2. | for the triangular loop abc, the induced current is clockwise. |
3. | for the irregularly shaped loop abcd, the induced current is anti-clockwise. |
4. | none of these. |
A conducting circular loop is placed in a uniform magnetic field, \(B=0.025~\text{T}\) with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of \(1~\text{mm s}^{-1}\). The induced emf, when the radius is \(2~\text{cm}\), is:
1. \(2\pi ~\mu\text{V}\)
2. \(\pi ~\mu\text{V}\)
3. \(\dfrac{\pi}{2}~\mu\text{V}\)
4. \(2 ~\mu \text{V}\)
1. | twice per revolution. |
2. | four times per revolution. |
3. | six times per revolution. |
4. | once per revolution. |