Electron Beam worksheet

 

1        (i)      beam current or intensity is reduced (1)
(because) fewer electrons are emitted (per sec) from the filament (1)
[or no beam as no electrons emitted if voltage of A
reduced enough (1)
(only)]

(ii)     electrons travel faster [or more kinetic energy] (1)
(because the force of) attraction to the anode is greater (1)                                    4

[7]

          2   (a)           KE  = 1.6 x 10-19 x 25 x 103;

         

(b)     A calculation to include:

1. K.E. = ½ x m x v2;

2. 4 x 10-15 = 0.5 x 9.1 x 10-31 x v2;

3. v = 9.4 x 107 ms^-1;                                                                                           3

.        

3        current = charge flow/ second or I = Q/t;
            = 9.0 × 1015/s × 1.6 × 10 –19C;
            = 1.4 × 10–3A;                                                                                                 3