Two identically charged particles A and B initially at rest, are accelerated by a common potential difference V. They enter into a transverse uniform magnetic field B. If they describe a circular path of radii respectively, then their mass ratio is:
1.
2.
3.
4.
A charge having q/m equal to 108 c/kg and with velocity 3 × 105 m/s enters into a uniform magnetic field B = 0.3 tesla at an angle 30º with the direction of field. Then the radius of curvature will be:
1. 0.01 cm
2. 0.5 cm
3. 1 cm
4. 2 cm
An electron having mass 'm' and kinetic energy E enter in a uniform magnetic field B perpendicularly. Its frequency will be:
1.
2.
3.
4.
In the Thomson mass spectrograph where \(\vec{E}\perp\vec{B}\) the velocity of the undeflected electron beam will be:
1. \(\frac{\left| \vec{E}\right|}{\left|\vec{B} \right|}\)
2. \(\vec{E}\times \vec{B}\)
3. \(\frac{\left| \vec{B}\right|}{\left|\vec{E} \right|}\)
4. \(\frac{E^{2}}{B^{2}}\)
If a charge '\(q\)' moves with velocity \(v\), in a region where electric field (\(E\)) and magnetic field (\(B\)) both exist, then force on it is:
1. \(q(\vec{v} \times \vec{B})\)
2. \(q \vec{E}+{q}(\vec{v} \times \vec{B})\)
3. \( q \vec{E}+q(\vec{B} \times \vec{v})\)
4. \(q\vec{B}+{q}(\vec{E} \times \vec{v})\)
1. | the speed of the particle remains unchanged. |
2. | the direction of the particle remains unchanged. |
3. | the acceleration remains unchanged. |
4. | the velocity remains unchanged. |
A very long straight wire carries a current I. At the instant when a charge +Q at point P has velocity , as shown, the force on the charge is
1. Along ox
2. Opposite to oy
3. Along oy
4. Opposite to ox