Ionized hydrogen atoms and \(\alpha\text-\)particles with the same momenta enter perpendicular to a constant magnetic field, \(B\). The ratio of their path radii \(r_\text{H}:r_\alpha\) will be:
1. | \(1:4\) | 2. | \(2:1\) |
3. | \(1:2\) | 4. | \(4:1\) |
To maximise the magnetic field caused by a small element of a current-carrying conductor at a point, the angle between the element and the line connecting the element to the point P must be:
1. | 0º | 2. | 90º |
3. | 180º | 4. | 45º |
Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd 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
When a charged particle with velocity is subjected to an induction magnetic field , the force on it is non-zero. What does this imply?
1. | angle between and is necessarily 90o. |
2. | angle between and can have any value other than 90o. |
3. | angle between and can have any value other than zero and 180o. |
4. | angle between and is either zero or 180o. |
A beam of electrons passes un-deflected through mutually perpendicular electric and magnetic fields. Where do the electrons move if the electric field is switched off and the same magnetic field is maintained?
1. | in an elliptical orbit. |
2. | in a circular orbit. |
3. | along a parabolic path. |
4. | along a straight line. |
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential V and then made to describe semi-circular paths of radius R using a magnetic field B. If V and B are kept constant, the ratio of \(\big(\frac{\text{Charge on the ion}}{\text{Mass of the ion}} \big)\) will be proportional to:
1.
2.
3.
4. R
If a charged particle (charge q) is moving in a circle of radius R at a uniform speed v, then the value of its associated magnetic moment μ will be:
1.
2.
3.
4.
A particle of mass \(m\), charge \(Q\), and kinetic energy \(T\) enters a transverse uniform magnetic field of induction \(\vec B\). What will be the kinetic energy of the particle after seconds?
1. | \(3~\text{T}\) | 2. | \(2~\text{T}\) |
3. | \(\text{T}\) | 4. | \(4~\text{T}\) |
A closed-loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR, and RQ are F1, F2, and F3 respectively, and are in the plane of the paper and along the directions shown,
then which of the following forces acts on the segment QP?
1.
2.
3.
4.
1. | 8 N in - z-direction. |
2. | 4 N in the z-direction. |
3. | 8 N in the y-direction. |
4. | 8 N in the z-direction. |