Electric Power Transmission - Physics Jamb Past Questions and Answers

Question 11 :

• JAMB 1998

A transformer which can produce 8V from a 240v a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in the primary coil.

A. 0.625A
B. 1.600A
C. 2.500A
D. 6.250A

Question 12 :

• JAMB 2010

Power supply is transmitted at a very high voltage and low current in order to

A. Make pass through the trasformers
B. Increase the power supply
C. Make it travel fast
D. Prevent overheating of the coil