In a chamber, a uniform magnetic field of 6.5 G (1 G = 10^–4 T) is maintained. An electron is shot into the field with a speed of 4.8 ×${10}^6$ m s^–1 normal to the field. the radius of the circular orbit is:
(e = 1.6 × 10^–19 C, $m_e$ = 9.1×10^–31 kg)

1.4.2 cm
2. 5.3 cm
3. 4.7 cm
4. 5.2 cm

An electron emitted by a heated cathode and accelerated through a potential difference of 2.0 kV, enters a region with a uniform magnetic field of 0.15 T. if the field is transverse to its initial velocity, the radius of the circular path is:

1. 2.10 mm
2. 0.11 mm
3. 1.01 mm
4. 0.12 mm

What is the magnitude of magnetic force per unit length on a wire carrying a current of \(8~\text{A}\) and making an angle of \(30^{\circ}\) with the direction of a uniform magnetic field of \(0.15~\text{T}\)?

A 3.0 cm wire carrying a current of 10 A is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be 0.27 T. What is the magnetic force on the wire?

1.\(8.1 \times 10^{-2} \ N\)
2.\(9.8 \times 10^{-2} \ N\)
3. \(7.6 \times 10^{-2} \ N\)
4.\(6.8 \times 10^{-2} \ N\)

A straight horizontal conducting rod of length 0.45 m and mass 60 g is suspended by two vertical wires at its ends. A current of 5.0 A is set up in the rod through the wires. (a) What magnetic field should be set up normally to the conductor in order that the tension in the wires is zero?

1. 0.13 T
2. 0.06 T
3. 0.26 T
4. 0.18 T

A uniform magnetic field of 1.5 T exists in a cylindrical region of a radius of 10.0 cm, its direction parallel to its axis along east to west. A wire carrying a current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if the wire intersects the axis?

1. 3.4 N vertically upward direction.
2. 2.1 N vertically upward direction.
3. 3.4 N vertically downward direction.
4. 2.1 N vertically downward direction.

A monoenergetic (18 keV) electron beam initially in the horizontal direction is subjected to a horizontal magnetic field of 0.04 G normal to the initial direction. The up or down deflection of the beam over a distance of 30 cm is:  $\left(m_e=9.11\times {10}^{-31} kg\right).$

1. 3.9 mm
2. 2.7 mm
3. 4.2 mm
4. 5.1 mm