A conducting rod is moved with a constant velocity \(v\) in a magnetic field. A potential difference appears across the two ends,
a. | \(\overrightarrow v \|\overrightarrow l\) | ifb. | if \(\overrightarrow v \|\overrightarrow B\) |
c. | \(\overrightarrow l \|\overrightarrow B\) | ifd. | none of these |
Choose the correct option:
1. | (a), (b) | 2. | (b), (c) |
3. | (d) only | 4. | (a), (d) |
A rod of length \(l\) rotates with a uniform angular velocity \(\omega\) about its perpendicular bisector. A uniform magnetic field \(B\) exists parallel to the axis of rotation. The potential difference between the two ends of the rod is:
1. zero
2. \(\frac{1}{2}Bl\omega ^{2}\)
3. \(Bl\omega ^{2}\)
4. \(2Bl\omega ^{2}\)
1. | \(vBl\) | 2. | \(vBl \over 2\) |
3. | \({\sqrt 3 \over 2}vBl\) | 4. | \({1 \over \sqrt 3}vBl\) |
1. | increases continuously. |
2. | decreases continuously. |
3. | first increases and then decreases. |
4. | remains constant throughout. |
1. | falls with uniform velocity. |
2. | \(g\). | accelerates down with acceleration less than
3. | \(g\). | accelerates down with acceleration equal to
4. | moves down and eventually comes to rest. |
1. | \(\dfrac{\mu_0A}{L}\cdot N\) | 2. | \(\dfrac{\mu_0A}{L}\cdot N^2\) |
3. | \(\dfrac{\mu_0L^3}{A}\cdot N\) | 4. | \(\dfrac{\mu_0L^3}{A}\cdot N^2\) |