Electric and magnetic fields both exert forces on charged particles. The motion of charged particles in these fields can be determined and used in particle accelerators.
Select the most accurate description of electric field lines.
Lines around a charged object which determine the force on a mass in the field
Lines around a charged object which determine the force on another charged object
Lines around a charged object which determine the energy of another charged object
In which direction do the arrows of electric field lines point?
From negative to positive charge
From positive to negative charge
Perpendicular to the field lines
How can the unit of electric potential, the volt , also be expressed?
Coulombs per joule
Joules per coulomb
Calculate the kinetic energy of an electron of charge accelerated by a potential difference of .
An electron of mass has a kinetic energy of . Calculate the speed of the electron.
If a vertical wire has a downward flowing current of electrons describe the resulting magnetic field.
Concentric circles with arrows pointing clockwise
Concentric circles with arrows pointing anticlockwise
Lines pointing outward from the wire
A magnetic field is set up going into the screen and a wire carrying an electron current flows left to right across the field.
In which direction will the wire experience a force?
Towards the bottom of the screen
Towards the top of the screen
To the right
An electron moving left to right enters a magnetic field pointing out of the screen. Describe the motion of the electron just as it enters the field.
Accelerated to the right
An electron is travelling through a large area subject to a strong magnetic field.
Which of the following statements best describes its path?
Circular if the direction of the charge is parallel to the magnetic field lines
Straight if the direction of the charge is perpendicular to the magnetic field lines
Circular if the direction of the charge is perpendicular to the magnetic field lines
What use is made of a strong magnetic field inside a cyclotron?
To accelerate charged particles to a greater speed
To ensure the charged particles move in a circular path
To increase the charge on the particle