Question 1
-
(a) sketch the circuit symbol for the following components:
(i)crystal diode; (ii)NPN transistor.
(b) State Ohm’s law.
(c) The instantaneous voltage applied to a circuit is expressed as
.
Calculate the:
- r.m.svalue;
- peak-to-peak value;
Observation
The expected answers were:
(a) (i) Crystal diode
Basic diagram of any/specific diode ( Zener, LED etc)
(ii) NPN transistor
(b) Ohm’s law states that the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance provided the temperature remains constant.
OR
Ohm’s law states that the current flowing through a metallic conductor is directly
proportional to the applied voltage provided the temperature (and other physical quantities) remain constant.
Mathematical expression without constants
( c) 
.
= 42.4V.
= 2 x 60
= 120V.
The question was well answered by candidates.