What is the magnetic dipole moment of the given loop?
1. | \({ 5 \over 2} \pi R^2I\) | 2. | \(3 \pi R^2I\) |
3. | \({ 3 \over 2} \pi R^2I\) | 4. | \(5 \pi R^2I\) |
A closed-loop (of any shape) carrying current lies in the x-y plane. What happens when a uniform magnetic field B is present in the region such that the loop experiences zero force?
1. | B acts along the x-axis |
2. | B acts along the y-axis |
3. | B acts along the z-axis |
4. | B can act along any of the above direction for the net force to be zero |
A galvanometer of resistance 240 Ω allows only 4% of the main current after connecting a shunt resistance. What is the value of shunt resistance?
1. 10
2. 20
3. 8
4. 5
A circular loop with a radius of 20 cm is placed in a uniform magnetic field B = 2T in the XY plane as shown in the figure. If the loop carries a current of i = 1 A, then the magnitude of torque acting on the loop will be:
1. 0.25 N-m
2. 5.2 N-m
3. 2.5 N-m
4. 0.52 N-m
The dots in the figure depict a magnetic field that is perpendicular to the plane of the paper and emanates from it. The trajectory of a particle in the plane of the paper is depicted by the curve ABC. What exactly is the particle?
1. | Proton. | 2. | Electron. |
3. | Neutron. | 4. | It cannot be predicted. |
If an electron of velocity is subjected to a magnetic field of \(4\hat{\mathrm{k}}\) :
1. | the speed will change. |
2. | the direction will change. |
3. | both (1) and (2) |
4. | none of the above |
A positively charged particle descends vertically. In which direction will the horizontal component of the earth's magnetic field deflect?
1. east
2. west
3. north
4. south
Which of the following graphs correctly represents the variation of magnetic field induction with distance due to a thin wire carrying current?
1. | 2. | ||
3. | 4. |
If the planes of two identical concentric coils are perpendicular and the magnetic moment of each coil is \(\mathrm M,\) then the resultant magnetic moment of the two-coil system will be:
1. | \(\mathrm M\) | 2. | \(\sqrt{2}\mathrm M\) |
3. | \(3\mathrm M\) | 4. | \(2\mathrm M\) |
When a 12 Ω resistor is connected in parallel with a moving coil galvanometer, its deflection reduces from 50 divisions to 10 divisions. What will be the resistance of the galvanometer?
1. 24 Ω
2. 36 Ω
3. 48 Ω
4. 60 Ω