Chapter 17: Motion of a charged particle in a magnetic field

In an electric field, the acceleration of a particle doesn't depend on its mass.

• true

• false

In a uniform electric field. the trajectory of a charged particle is circular.

• true

• false

The power developed by a magnetic force is zero.

• true

• false

The energy would an electron receive when accelerated under a voltage of 2000V is ……… (-e = -1.6x10^-19C)

• 3.2x10^-16C

• -3.2x10^-16C

• 1.25x10^-16C

• -1.25x10^-16C

An electron of mass m = 9.1x10^-31kg and charge q = -1.6x10^-19C enters a uniform electric field of magnitude E = 10³V/m. The weight of the electron is negligible with respect to the electric force because ……….

• F >>>> w

• w>>>>> F

• w = F

• m <<< q

In an oscilloscope, the deflection of the spot on the screen is …………………….. to the applied voltage.

• inversely proportional

• directly proportional

• equal

• independent

A charged particle, at rest or in motion, is always submitted to an electric force when placed in an electric field.

• true

• false

A proton of mass m = 1.67x10^-27kg and charge q = 1.6x10^-19C is accelerated from rest in vacuum under a voltage U thus reaching V = 2x10⁵m/s. Calculate U

• U = 1.04x10^-3V

• U = 100V

• U = 208.75V

• 20V