1. | \(0\) | 2. | \(1.2\times 10^{-4}~\text{T}\) |
3. | \(2.1\times 10^{-4}~\text{T}\) | 4. | None of these |
An element \(\Delta l=\Delta x \hat{i}\) is placed at the origin and carries a large current of \(I=10\) A (as shown in the figure). What is the magnetic field on the \(y\text-\)axis at a distance of \(0.5\) m? \((\Delta x=1~\text{cm})\)
1. | \(6\times 10^{-8}~\text{T}\) | 2. | \(4\times 10^{-8}~\text{T}\) |
3. | \(5\times 10^{-8}~\text{T}\) | 4. | \(5.4\times 10^{-8}~\text{T}\) |
A long solenoid carrying a current produces a magnetic field \(B\) along its axis.
If the current is doubled and the number of turns per cm is halved, what will be the new value of the magnetic field?
1. \(B/2\)
2. \(B\)
3. \(2B\)
4. \(4B\)
What properties will a galvanometer that is acting as a voltmeter have?
1. | high resistance in series with its coil | 2. | low resistance in parallel with its coil |
3. | low resistance in series with its coil | 4. | high resistance in parallel with its coil |
1. | \({G \over (S+G)}\) | 2. | \({S^2 \over (S+G)}\) |
3. | \({SG \over (S+G)}\) | 4. | \({G^2 \over (S+G)}\) |
(a) | \(\oint B\cdot dl= \mp 2\mu_0 I\) |
(b) | the value of \(\oint B\cdot dl\) is independent of the sense of \(C\). |
(c) | there may be a point on \(C\) where \(B\) and \(dl\) are perpendicular. |
(d) | \(B\) vanishes everywhere on \(C\). |
Which of the above statements are correct?
1. (a) and (b)
2. (a) and (c)
3. (b) and (c)
4. (c) and (d)
Assertion (A): | \(\alpha\)-particle enters a uniform magnetic field perpendicularly with the same speed, then the time period of revolution of the \(\alpha\)-particle is double that of a proton. | If a proton and an
Reason (R): | In a magnetic field, the time period of revolution of a charged particle is directly proportional to mass. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |