Basic Electrical Theory


1. The Coulomb is:

  • A) The quantity of electricity that flows past a given point in an electric circuit when a current of one ampere is maintained for one second.
  • B) The difference of electrical charge between two points in an electrical circuit.
  • C) The opposition to the charge between two points in a conductor.
  • D) A measure of a material’s ability to conduct an electrical current.
  • E) The rate at which electrical energy is transferred at a given point over a set period of time.

Correct Answer: A


2. Electrical Power is:

  • A) The quantity of electricity that flows past a given point in an electric circuit when a current of one ampere is maintained for one second.
  • B) The difference of electrical charge between two points in an electrical circuit.
  • C) The opposition to the charge between two points in a conductor.
  • D) A measure of a material’s ability to conduct an electrical current.
  • E) The rate at which electrical energy is transferred at a given point over a set period of time.

Correct Answer: E


3. Which is the correct formula for Charge:

  • A) Current × time
  • B) Energy / Charge
  • C) Voltage ÷ Current
  • D) Voltage × Current
  • E) Power × time

Correct Answer: A


4. Which of the following quantities has the SI unit as Watt?

  • A) Resistance
  • B) Charge
  • C) Conductance
  • D) Power
  • E) Potential Difference

Correct Answer: D


5. Which of the following quantities has the unit Ohm?

  • A) Resistance
  • B) Charge
  • C) Conductance
  • D) Power
  • E) Potential Difference

Correct Answer: A


6. If a current of 3A flows for 5 minutes, find the quantity of charge:

  • A) 900C
  • B) 15C
  • C) 8C
  • D) 5C
  • E) 3C

Correct Answer: A

Explanation:


7. What is the potential difference when an electronic circuit has a power of 20W with a charge of 5 Coulombs?

  • A) 4V
  • B) 5V
  • C) 20V
  • D) 25V
  • E) 100V

Correct Answer: A

Explanation:


8. What is the unit of potential difference?

  • A) Ohm
  • B) Volt
  • C) Watt
  • D) Ampere
  • E) Coulomb

Correct Answer: B


9. What is the resistance of a circuit when a 10V supply causes a current of 0.5A to flow?

  • A) 20 Ohms
  • B) 0.05 Ohms
  • C) 0.05 Amps
  • D) 20 Volts
  • E) 0.05 Volts

Correct Answer: A

Explanation:


10. A power supply provides a DC source of 10V with a current of 2A for 20 minutes. How much power is used?

  • A) 1W
  • B) 2W
  • C) 5W
  • D)10W
  • E) 20W

Correct Answer: E

Explanation: