Question 2
(a) A resistor has a colour of red, green, orange and no band. Determine in ohms, its:
(a) A resistor has a colour of red, green, orange and no band. Determine in ohms, its:
- resistance;
- tolerance.
(b) Fig.2 a d.c. circuit.
Using the Kirchhoff’s Current Law, calculate:
- (i) I2;
- (ii) I4;
- (iii) I5.
Observation
The expected answers were:
(a) Red – 2, Green – 5, Orange – 103, No band – 20% = (25 x 103)Ω ± 20%
- (i) Resistance = 25 x 103 Ω = 25k Ω.
- (ii) Tolerance = 20% x 25000 = ±5000 Ω.
- (b) Using the Kirchhoff’s Current Law:
- (i) I1 = I2 + I3
4 = I2 + 3
I2 = 1A.
- (ii) 2 = I4 + I6
1 + I4 = 2
I4 = 1A.
- (iii) 3 = I4 + I5
3 = 1 + I5
I5 = 2A.
- (c)Voltage drop across R5 =VR5 = I2R5.
Many candidates were unable to correctly apply the Kirchhoff’s Current Law.