Question 1
AIM: To verify Kirchhoff’s law in d.c circuits.
- Connect the circuit as shown in figure 1.
- Ask the supervisor to check the circuit connection.
- Copy Table 1 into your answer booklet.
- Close switches S1 and S2.
- Measure and record the voltages across each of the resistors as shown in Table 1
- Open switches S1 and S2.
- Evaluate:
- VA = VR1 + VR2 – VR3 – V1
- VB = VR4 –V2 +VR5 – VR3
- Comment on the results obtained in steps (g)(i) and (g)(ii)
Observation
The expected answers were;
Correct circuit connection
(g) (i) VA = VR1 + VR2 - VR3 - V1
= 0.26 + 1.45 - 0.21 - 1.5
= 0
(ii) VB = VR1- V2+ VR5+ VR3
= 0.99 - 1.5 + 0.30 + 0.21
= 0
(h) The VA = 0, VB = 0
OR
The results obtained in Step (g) verified Kirchhoff’s Voltage Law.
OR
The sum of voltage in Loop A is equal to zero and
The sum of voltage drops across resistors in Loop B is equal to zero
OR
Any other reasonable comment.
The question required candidates to use the apparatus to connect a circuit that verifies Kirchhoff’s voltage law. Candidates did well in carrying out the instructions. The circuit was connected as expected but they did not do well in taking their readings which affected their performance.