Electrical Energy and Power - Jamb Physics Past Questions and Answers

Question 16:

• JAMB 1995

If the maximum voltage across a 100ohms resistor is 20V, then the maximum power it can dissipate is

A. 5.00W
B. 4.00W
C. 2.00W
D. 25W

Question 17:

• JAMB 1995

The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be

A. 3V
B. 6V
C. 24V
D. 48V

Question 18:

• JAMB 1995

The fig above shows two similar bulbs X and Y connected to suitable power supply with F as an appropriate fuse rating, if the filament of X breaks then the

A. Brightness Of Y will reduce
B. Brightness Of Y will remain constant
C. Brightness Of Y will increase
D. Fuse F will blow

Question 19:

• JAMB 1997

What is the total electrical energy consumed by using an electric cooker rated 1000W for 5 hrs?

A. 5.3 x 10³J
B. 6.5 X 10³J
C. 1.8 X 10⁷J
D. 2.3 X 10⁷J

Question 20:

• JAMB 1998

A man whose mass is 80kg climbs a staircase in 20s and expends power of 120W. Find the height of the staircase.[g = 10ms^-2]

A. 1.8m
B. 2.0m
C. 2.5m
D. 3.0m