A rectangular loop carrying a current \(I_1\), is situated near a long straight wire carrying a steady current \(I_2\).
If the wire is parallel to one of the sides of the loop and is in the plane of the loop as shown in the figure, then the current loop will:
1. | move away from the wire. |
2. | move towards the wire. |
3. | remain stationary. |
4. | rotate about an axis parallel to the wire. |
1. | \(N\) is small | 2. | \(B\) is small |
3. | \(A\) is small | 4. | \(C\) is small |
A milliammeter of \(10\) mA has a coil resistance of \(1~\Omega\). To use it as an ammeter of range \(1\) A, the required shunt must have a resistance of:
1. \(\frac{1}{101}~\Omega \)
2. \(\frac{1}{100}~\Omega \)
3. \(\frac{1}{99}~\Omega \)
4. \(\frac{1}{9}~\Omega \)
1. | \(0^{\circ}\) | 2. | \(90^{\circ}\) |
3. | \(180^{\circ}\) | 4. | \(45^{\circ}\) |
If the value of integral \(\oint \vec {B} \cdot \vec {dl}\) for the loops \(C_1, C_2,~\text{and}~C_3\) \(2\mu_0, 4\mu_0~\text{and}~\mu_0\) in the units of N/A, respectively, then:
1. | \(I_1=3 A\) into the paper | 2. | \(I_2=3 A\) out of the paper |
3. | \(I_3=0\) | 4. | \(I_3=1 A\) out of the paper |
A ring of radius \(R\) carries a linear charge density \(\lambda\). It is rotating with angular speed \(\omega\) about an axis passing through the centre and perpendicular to the plane. What is the magnetic field at its centre?
1. | \(\dfrac{3 \mu_{0} \lambda \omega}{2}\) | 2. | \(\dfrac{\mu_{0} \lambda \omega}{2}\) |
3. | \(\dfrac{\mu_{0} \lambda \omega}{\pi}\) | 4. | \(\mu_{0} \lambda \omega\) |
1. | \(1:4\) | 2. | \(2:1\) |
3. | \(1:2\) | 4. | \(4:1\) |
Two circular coils \(1\) and \(2\) are made from the same wire but the radius of the \(1\)st coil is twice that of the \(2\)nd coil. What is the ratio of the potential difference applied across them so that the magnetic field at their centres is the same?
1. \(3\)
2. \(4\)
3. \(6\)
4. \(2\)
1. | Angle between \(\vec v\) and \(\vec {B}\) is necessarily \(90^{\circ}\). |
2. | Angle between \(\vec v\) and \(\vec {B}\) can have any value other than \(90^{\circ}\). |
3. | Angle between \(\vec v\) and \(\vec {B}\) can have any value other than zero and \(180^{\circ}\). |
4. | Angle between \(\vec v\) and \(\vec {B}\) is either zero or \(180^{\circ}\). |