physics

An electric motor is a machine that converts?

A. mechanical energy into electrical energy B. electrical energy into mechanical energy C. high voltage to low voltage D. low…

6 years ago

A bar magnet is placed near and lying along the axis of a solenoid connected to a galvanometer. The pointer of the galvanometer shows no deflection when.

A. the magnet is moved away from the stationary solenoid B. the solenoid is moved away from the stationary magnet…

6 years ago

Lenz’s law of electromagnetic induction states that?

A. a force is exerted on a current-carrying conductor in a magnetic field B. electromotive force id induced in a…

6 years ago

Two capacitors if capacitance 0.4μF and 0.5μF are connected in parallel and charged to a p.d. of 50V, Determine the total charge acquired.

A. 45μC B. 25μC C. 20μC D. 10μC Correct Answer: Option A A. 45μC Explanation C = C1+C2 = 0.4…

6 years ago

Which of the following statements explains lost volt in an electric circuit? The

A. total p.d from a source to maintain a flow of current through the circuit as well as the source…

6 years ago

A parallel plate capacitor of capacitance 600μF has a potential difference of 200V between its plates. Calculate the charge on either plate of the capacitor.

A. 1.2C B. 3.3C C. 3330.0C D. 12.0000.0C Correct Answer: Option A A. 1.2C Explanation Q = CV = 600…

6 years ago

The ability of a material to store an electric charge when its plates are at different potentials is referred to as its?

A. conductance B. inductance C. capacitance D. resistance Correct Answer: Option C C. capacitance

6 years ago

An electric lamp is rated 240V, 40W. What is the cost of running the lamp for 72 hours if the electricity authority charges N2.50 per kWh?

A. N7.20 B. N18.00 C. 180.00 D. N720.00 Correct Answer: Option A A. N7.20 Explanation Cost = (Pt/1000) x cost…

6 years ago

A chemical cell of internal resistance 1Ω supplies electric current to an external resistor of resistance 3Ω. Calculate the efficiency of the cell.

A. 75% B. 50% C. 33% D. 25% Correct Answer: Option A A. 75% Explanation R = r1+ R =…

6 years ago

A ray of light is incident normally on a plan mirror. If the incident ray is kept fixed while the mirror is rotated through an angle of 30°, determine the initial and final angles of reflection respectively

A. 0° and 60° B. 90° and 30° C. 0° and 30° D. 90° and 60° Correct Answer: Option D…

6 years ago
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