Jamb Physics 2001 Past Questions and Answers

Question 21:

• JAMB 2001

A working electric motor takes a current of 1.5 A when the p.d across it is 250V. If its efficiency is 80%, the power output is

A. 300.0W
B. 469.0W
C. 133.0W
D. 4.8W

Question 22:

• JAMB 2001

The cost of running five 60 W lamps and four 100 W lamps for 20 hours if electrical energy cost #10.00 per kwh is

A. 280.00
B. 160.00
C. 120.00
D. 140.00

Question 23:

• JAMB 2001

In a Daniel cell, the depolarizer, positive and negative electrodes are respectively

A. Copper sulphate, copper and zinc
B. Manganese dioxide, carbon and zinc
C. Sulphuric acid, lead oxide and lead
D. Potassium hydroxide, nickel and iron.

Question 24:

• JAMB 2001

when a piece of rectangular glass block is inserted between two parallel capacitor,at constant plate area and distance of separation, the capacitance of the capacitor will

A. Increase
B. Decrease
C. Decrease then increase
D. Remain constant

Question 25:

• JAMB 2001

the ratio of electrostatic force F_E to gravitational force F_G between two protons each of charge e and mass m, at a distance d is

A. E/4πԐoGm
B. E²/Gm²
C. Gm²/4πԐoe²
D. E²/4πԐoeGm²