Q. No.A long straight wire of radius \(R\) carries a uniformly distributed current \(i.\) The variation of magnetic field \(B\) from the axis of the wire is correctly presented by the graph?
1.
2.
3.
4.
An electron enters a chamber in which a uniform magnetic field is present as shown.
An electric field of appropriate magnitude is also applied so that the electron travels undeviated without any change in its speed through the chamber. We are ignoring gravity. Then, the direction of the electric field is:
| 1. | opposite to the direction of the magnetic field. |
| 2. | opposite to the direction of the electron's motion. |
| 3. | normal to the plane of the paper and coming out of the plane of the paper. |
| 4. | normal to the plane of the paper and into the plane of the paper. |
Two toroids \(1\) and \(2\) have total no. of turns \(200\) and \(100\) respectively with average radii \(40~\text{cm}\) and \(20~\text{cm}\) respectively. If they carry the same current \(i,\) what will be the ratio of the magnetic fields along the two loops?
1. \(1:1\)
2. \(4:1\)
3. \(2:1\)
4. \(1:2\)
An ammeter reads up to \(1\) A. Its internal resistance is \(0.81\) \(\Omega\). To increase the range to \(10\) A, the value of the required shunt is:
1. \(0.09~\Omega\)
2. \(0.03~\Omega\)
3. \(0.3~\Omega\)
4. \(0.9~\Omega\)
| 1. | \(1:4\) | 2. | \(2:1\) |
| 3. | \(1:2\) | 4. | \(4:1\) |
A cylindrical conductor of radius \(R\) is carrying a constant current. The plot of the magnitude of the magnetic field \(B\) with the distance \(d\) from the centre of the conductor is correctly represented by the figure:
| 1. |  |
2. |  |
| 3. |  |
4. |  |
A millivoltmeter of \(25~\text{mV}\) range is to be converted into an ammeter of \(25~\text{A}\) range. The value (in ohm) of the necessary shunt will be:
1. \(0.001\)
2. \(0.01\)
3. \(1\)
4. \(0.05\)
| 1. | \({1 \over 499}G\) | 2. | \({499 \over 500}G\) |
| 3. | \({1 \over 500}G\) | 4. | \({500 \over 499}G\) |
Moving perpendicular to field \(B\), a proton and an alpha particle both enter an area of uniform magnetic field \(B\). If the kinetic energy of the proton is \(1~\text{MeV}\) and the radius of the circular orbits for both particles is equal, the energy of the alpha particle will be:
1. \(4~\text{MeV}\)
2. \(0.5~\text{MeV}\)
3. \(1.5~\text{MeV}\)
4. \(1~\text{MeV}\)
If a square loop \({ABCD}\) carrying a current \(i\) is placed near and coplanar with a long straight conductor \({XY}\) carrying a current \(I,\) what will be the net force on the loop?
1. \(\dfrac{\mu_0Ii}{2\pi}\)
2. \(\dfrac{2\mu_0IiL}{3\pi}\)
3. \(\dfrac{\mu_0IiL}{2\pi}\)
4. \(\dfrac{2\mu_0Ii}{3\pi}\)
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