1.	The diagram shows the path of an electron in a uniform electric field between two parallel conducting plates AB and CD. The electron enters the field at a point midway between A and D. It leaves the field at B.

(a)	Mark on the diagram the direction of the electric field lines.
(1)
(b)	(i)	The conducting plates are 5.0 cm apart and have a potential difference of 250 V between them. Calculate the force on the electron due to the electric field.
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Force = ...............................................
(3)
(ii)	State the direction of this force on the electron and explain why it does not affect the horizontal velocity of the electron.
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(2)

(c)	To leave the electric field at B the electron must enter the field with a speed of 1.30 × 107 m s–1. Calculate the potential difference required to accelerate an electron from rest to this speed.
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Potential difference = .........................
(3)
(d)	A very thin beam of electrons enters a uniform electric field at right angles to the field. The electrons have a range of speeds.
(i)	Draw a diagram to show the shape of the beam as it moves through the field.

(ii)	On your diagram label which electrons have the fastest speed.
(2)
(Total 11 marks)

2.	The diagram shows two parallel plates with a potential difference of 3000 V applied across them. The plates are in a vacuum.

	On the diagram sketch the electric field pattern in the region between the plates.
(2)
	On the same diagram sketch and label two equipotential lines.
(1)

	The plates are 25 mm apart. Show that the force experienced by an electron just above the bottom plate is about 2 × 10–14 N.
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(3)
	Complete the graph to show how the force on the electron varies with the distance of the electron from the bottom plate.

(2)
	This force causes the electron to accelerate.
	The electron is initially at rest in contact with the bottom plate when the potential difference is applied. Calculate its speed as it reaches the upper plate.
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Speed = ................................................................
(3)
(Total 11 marks)

3.	An isolated charged metallic sphere is brought close to an identical earthed sphere that initially was uncharged. Part of the resultant electric field and some of its equipotential lines are shown.

	On the diagram mark the sign of the charge on each sphere.
(2)
	Draw an arrow on one of the field lines to indicate its direction.
(1)
	Expressing your answers in eV, state how much work is done
(i)	against the field in taking an electron from C to D,
Work done = ................................................... eV
(ii)	against the field in taking an electron from C to A.
Work done = ................................................... eV
(3)
(Total 6 marks)