What is the best method of demagnetizing a steel bar magnet?
Hammering
Heating it
Rough handling it
Solenoid method
Correct answer is D
No explanation has been provided for this answer.
PHCN measures its electrical energy in
W
KWh
Wh
J
Correct answer is B
No explanation has been provided for this answer.
A circuit has a resistance of 200Ω. The resistance of the circuit can be reduced to 120Ω when
A 300Ω resistor is connected to it in parallel
An 80Ω resistor is conneceted to it in series
A 150Ω resistor is connected to it in parallel
A 240Ω resistor is connected to it in series
Correct answer is A
No explanation has been provided for this answer.
The maximum power transfer occur in a cell when the external resistance is
Twice the internal resistance of the cell
The same as the internal resistance of the cell
Greater than the internal resistance of the cell
Less than the internal resistance of the cell
Correct answer is B
the maximum power transfer theorem states that the maximum power is transferred from a source e.g. cell or battery to its load (external resistance) when the resistance of the load is equal to the internal resistance of the source.
What charge is stored in a 0.1F capacitor when a 10V supply is connected across it?
1C
5C
4C
2C
Correct answer is A
Q = CV = 0.1 x 10 = 1C