Electrical Energy and Power - Jamb Physics Past Questions and Answers

Question 41:

• JAMB 2007

A 40KW electric cable was uses to transmit electricity through a resistor of resistance 2.00Ω at 800V. The power loss as internal energy is

A. 4.0 x 10²W
B. 5.0 x 10²W
C. 4.0 x 10³W
D. 5.0 x 10³W

Question 42:

• JAMB 2008

A generator is on daily use and in the process, ten 60 W and five 40 W tungsten bulbs are on for the same time interval. the energy consumed daily is?

A. 0.96 kWh
B. 19.2 kWh
C. 9.60 kWh
D. 19.20 kWh

Question 43:

• JAMB 2008

I. for current amplification.
II. for voltage stabilization.
III. for power amplification.
IV. as a switch.
which of the above are the uses of transistor?

A. I,II,III and IV
B. I,III, and IV only
C. I, II and III only
D. I,II and IV only

Question 44:

• JAMB 2009

An electric lamp marked 240v, 60 W is left to operate for an hour. How much energy is generated by the filament?

A. 3.86 x 10⁵J
B. 3.56 x 10⁵J
C. 1.80 x 10⁴J
D. 2.16 x 10⁵J

Question 45:

• 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