Jamb Physics Past Questions
Question 11
Three 5 ohms resistors connected in parallel have a potential difference of 60v. applied across the combination. The current in each resistor is
- A. 4A
- B. 36A
- C. 12A
- D. 24A
- E. 10A
Question 12
Every house supplied with electricity is provided with a box of fuses so that
- A. the consumption of electricity can be recorded
- B. people residing in the house will not have an electric shock if they touch a live wire
- C. the total current drawn from the mains can be limited
- D. the voltage supply can be stabilized
- E. it serves as a standby supply when there is a power failure
Question 13
The electric supply from Kainji Dam is transmitted at high voltages of the order hundreds of kilovolts but is converted to domestic use of about 220 volts by
- A. commutators
- B. transistors
- C. valves and diodes
- D. rectifiers
- E. transformers
Question 14
A potential difference of 6v is used to produce a current of 5A for 200s through a heating coil. The heat produced is
- A. 4800 cal
- B. 6000 cal
- C. 2400J
- D. 240k cal
- E. 6000J
Question 15
Why is it impossible for the lines of force of an electric field to cross one another?
- A. like charges repel each other
- B. a charged particle is deflected by an eletric field
- C. like charges are arranged on the same line of force
- D. a positively charged particle can travel in only one direction at any time
- E. none of these is correct
