An introduction to electric circuits

What is electricity?

• Flow of atoms

• Resistor

• Insulator

• Flow of electric charge

What is a measuring instrument?

• Is a device used for determining the value or magnitude of a quantity or variable.

• Is a physical quantity.

• Is a measuring device

Which measuring instrument is used to measure voltmeter?

• Ohmmeter

• Voltmeter

• Ammeter

• Watt-meter

State ohm's law?

• Current is directly proportional to the voltage.

• Currently is directly proportional to the resistance.

• Voltage is directly proportional to the resistance.

• Power in a circuit.

Which formula is used to calculate power?

• P = VI

• P = I² R

• P = V² / R

• Q = It

State the SI unit of power.

• Amps (A)

• Watts (W)

• Volts (V)

• Ohms (Ω)

A battery of e.m.f. 15 V supplies a current of 2 A for 5 min. How much energy is supplied in this time?

• 9 KJ

• 900 J

• 1.2 KJ

• 400 J

A 20 V source of e.m.f. is connected across a circuit having a resistance of 400 Ω. Calculate the current flowing.

• 10 mA

• 50 mA

• 5 mA

• 1 mA

Three resistors of 100 Ω, 270 Ω and 470 Ω are connected in series. Calculate the total resistance of the circuit.

• 840 Ω

• 500 Ω

• 750 Ω

• 63.166 Ω

Resistances of 4 Ω and 12 Ω are connected in parallel across a 9 V battery. Determine the equivalent circuit resistance and the supply current.

• 3 Ω

• 3 A

• 5 Ω

• 5 A