Waec Physics 2005 Past Questions and Answers

Question 36:

• WAEC 2005

A parallel plate capacitor of capacitance 600\(\mu F\) has a potential difference of 200V between its plates. Calculate the charge on either plate of the capacitor

A. 1.2C
B. 3.3C
C. 3330.0C
D. 12.0000.0C

Question 37:

• WAEC 2005

a chemical cell of internal resistance 1\(\Omega\) supplies electric current to an external resistor of resistance 3\(\Omega\). Calculate the efficiency of the cell

A. 75%
B. 50%
C. 33%
D. 25%

Question 38:

• WAEC 2005

An electric lamp is rated 240V, 40W. What is the cost of running the lamp for 72 hours if the electricity authority charges N2.50 per kWh?

A. N7.20
B. N18.00
C. 180.00
D. N720.00

Question 39:

• WAEC 2005

Which of the following statements explains lost volt in an electric circuit? The

A. Total p.d from a source to maintain a flow of current through the circuit as well as the source
B. P.d to drive current through the circuit component except the source
C. P.d across all external components connected to the source of electricity
D. P.d across the internal resistance of the cell

Question 40:

• WAEC 2005

A constantan wire has a cross sectional area of 4 x 10^-8m² and a resistivity of 1.1 x 10^-6\(\Omega\)m. If a resistor of resistance 11\(\Omega\) is to be made from this wire, calculate the length of the wire required

A. 0.4m
B. 0.8m
C. 2.5m
D. 5.0m