Electrical Energy and Power - Jamb Physics Past Questions and Answers

Question 36:

• JAMB 2005

An electric device is rated 2000 W, 250 v. The correct fuse rating of the device is?

A. 9 A
B. 8 A
C. 6 A
D. 7 A

Question 37:

• JAMB 2005

A car battery rated 45 A H is charged with a charger whose rating is 2.5A.How long will it take to charge the battery full?

A. 10 hrs
B. 18 hrs
C. 20 hrs
D. 25 hrs

Question 38:

• JAMB 2006

An electric heater with a p.d of 240 V connected across its terminals has a total resistance of 960Ω. find the power rating of the heater.

A. 0.25 W
B. 4.00 W
C. 38.40W
D. 60.00W

Question 39:

• JAMB 2006

A 40 kW electric cable is used to transmit electricity through a resistor of resistance 2.0Ω at 800 V. 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 40:

• JAMB 2006

An engine of a car of power 80 kW moves on a rough road with a velocity of 32 ms^-1. The forces required to bring it to rest is

A. 2.56 x 10⁶N
B. 2.50 x 10⁶N
C. 2.80 x 10³N
D. 2.50 x 10³N