1. The main function of an electrical transformer is to:
A. Store electrical energy
B. Convert AC to DC
C. Change voltage levels
D. Regulate current flow
Answer: c) Change voltage levels
Rationale: Transformers are used to step up or step down the voltage
levels in alternating current circuits.
2. If the resistance in a circuit is halved while the voltage remains
constant, the current will:
A. Double
B. Remain the same
C. Halve
D. Become zero
Answer: a) Double
Rationale: According to Ohm’s law, I=VRI = \frac{V}{R}I=RV, if the
resistance is halved, the current will double, provided the voltage stays
the same.
3. What type of current does a battery provide?
,A. Alternating Current (AC)
B. Direct Current (DC)
C. Both AC and DC
D. None of the above
Answer: b) Direct Current (DC)
Rationale: A battery provides direct current (DC), where current flows
in one direction.
4. In an electrical circuit, the term "short circuit" refers to:
A. A circuit with high resistance
B. A circuit with no resistance
C. A circuit with low resistance
D. A circuit with alternating current
Answer: c) A circuit with low resistance
Rationale: A short circuit occurs when there is a path of very low
resistance, causing excessive current flow and potential damage to the
circuit.
5. What is the primary cause of resistance in conductors?
A. Lack of free electrons
B. High temperature
C. Interference from other electrical devices
, D. Collisions between electrons and atoms
Answer: d) Collisions between electrons and atoms
Rationale: Resistance in conductors arises due to the collisions between
free electrons and the atoms in the material, which impedes the flow of
current.
6. Which of the following materials is an insulator?
A. Copper
B. Aluminum
C. Rubber
D. Silver
Answer: c) Rubber
Rationale: Rubber is an insulator because it resists the flow of
electricity, unlike copper or aluminum, which are conductors.
7. What is the unit of electrical charge?
A. Coulomb
B. Ampere
C. Ohm
D. Volt
Answer: a) Coulomb
A. Store electrical energy
B. Convert AC to DC
C. Change voltage levels
D. Regulate current flow
Answer: c) Change voltage levels
Rationale: Transformers are used to step up or step down the voltage
levels in alternating current circuits.
2. If the resistance in a circuit is halved while the voltage remains
constant, the current will:
A. Double
B. Remain the same
C. Halve
D. Become zero
Answer: a) Double
Rationale: According to Ohm’s law, I=VRI = \frac{V}{R}I=RV, if the
resistance is halved, the current will double, provided the voltage stays
the same.
3. What type of current does a battery provide?
,A. Alternating Current (AC)
B. Direct Current (DC)
C. Both AC and DC
D. None of the above
Answer: b) Direct Current (DC)
Rationale: A battery provides direct current (DC), where current flows
in one direction.
4. In an electrical circuit, the term "short circuit" refers to:
A. A circuit with high resistance
B. A circuit with no resistance
C. A circuit with low resistance
D. A circuit with alternating current
Answer: c) A circuit with low resistance
Rationale: A short circuit occurs when there is a path of very low
resistance, causing excessive current flow and potential damage to the
circuit.
5. What is the primary cause of resistance in conductors?
A. Lack of free electrons
B. High temperature
C. Interference from other electrical devices
, D. Collisions between electrons and atoms
Answer: d) Collisions between electrons and atoms
Rationale: Resistance in conductors arises due to the collisions between
free electrons and the atoms in the material, which impedes the flow of
current.
6. Which of the following materials is an insulator?
A. Copper
B. Aluminum
C. Rubber
D. Silver
Answer: c) Rubber
Rationale: Rubber is an insulator because it resists the flow of
electricity, unlike copper or aluminum, which are conductors.
7. What is the unit of electrical charge?
A. Coulomb
B. Ampere
C. Ohm
D. Volt
Answer: a) Coulomb
