Question
Fig. 11.1 shows an electron beam about to enter, at point A, the electric field between two charged metal plates.
(a) On Fig. 11.1, carefully draw the path of the electron beam between A and the line BC. [3]
The voltage across the plates is reversed. State what difference this makes to the path of the electron beam.
…………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………. [1] [Total: 4]
Answer/Explanation
Ans: (a) any downward deflection and no upward deflection curve, either all up or all down, from A to end of region between plates straight on from end of region between plates, towards BC (b) idea of deflection upwards/it goes upwards/it moves upwards no e.c.f.ignore opposite direction/opposite path
Question
(a) Describe, in terms of particles and the terminals of the battery, the movement of charge in an
electric circuit.
(b) Fig. 10.1 shows a lightning flash between a cloud and the ground beneath.
The charge built up on the cloud before the lightning flash is 0.60 C. This charge is completely
transferred to the ground by the lightning flash in 5.0 × \(10^{-5}\) s (0.000050 s).
(i) Calculate the current between the cloud and the ground.
current=
(ii) The potential difference (p.d.) between the cloud and the ground during the lightning flash is
2.5 × \(10^8\) V
Calculate the energy transferred during the lightning flash.
energy=
(iii) Suggest what happens to the energy calculated in (b)(ii).
Answer/Explanation
Answer
(a) Electrons / negative particles
Move (in circuit) from negative (terminal) to positive (terminal of battery)
(b)(i)(I =) Q / t OR 0.60 / 0.000050
12 000 A
(ii) (E=) I V t OR 12 000 × 2.5 × \(10^8\) × 0.000050
1.5 × \(10^8\) J
OR
1.5 × \(10^8\) J
(iii) Converted to any two of: thermal energy / heat, light and sound