#1
Which of the following materials is commonly used as an insulator in electrical distribution?
Rubber
ExplanationRubber is commonly used due to its high resistance to electricity.
#2
What is the function of a transformer in an electrical distribution system?
To increase voltage
ExplanationTransformers are used to step up or step down voltage levels efficiently.
#3
What is the purpose of a fuse in an electrical circuit?
To prevent overcurrent
ExplanationFuses protect circuits by interrupting the flow of current when it exceeds safe levels.
#4
Which of the following is a characteristic of an alternating current (AC) system?
Voltage and current vary periodically
ExplanationAC systems alternate direction periodically, resulting in varying voltage and current.
#5
Which type of transformer is commonly used to step up or step down voltage in electrical distribution?
Step-down transformer
ExplanationStep-down transformers reduce voltage levels for distribution.
#6
What is the main function of a distribution system in electrical engineering?
To distribute electrical power to end-users
ExplanationDistribution systems transmit electricity from power plants to consumers.
#7
Which of the following is a unit of electrical power?
Watt
ExplanationWatt is the standard unit of measurement for electrical power.
#8
What is the term for the phenomenon where a sudden rush of current flows into an electrical system after a disruption?
Power surge
ExplanationA power surge is a sudden increase in voltage that can damage equipment.
#9
What is the primary function of a circuit breaker?
To interrupt the flow of current in case of overload
ExplanationCircuit breakers protect circuits by stopping the flow of electricity when there's a fault.
#10
Which of the following is a component of a distribution transformer?
Core
ExplanationThe core provides a path for magnetic flux in a transformer.
#11
Which type of electrical distribution system uses a single-phase AC supply?
Split-phase system
ExplanationSplit-phase systems use a single-phase AC supply to distribute power.
#12
What is the purpose of the core in a transformer?
To provide a path for magnetic flux
ExplanationThe core directs magnetic flux between the transformer's windings.
#13
In a three-phase electrical system, what is the phase difference between each phase?
120 degrees
ExplanationEach phase is 120 degrees out of phase with the other two in a balanced system.
#14
What is the unit of measurement for electrical resistance?
Ohm
ExplanationOhm is the standard unit of electrical resistance.
#15
What is the effect of adding more windings to the primary coil of a transformer?
Increase in voltage
ExplanationMore windings on the primary coil lead to a higher voltage output.
#16
What is the efficiency of an ideal transformer?
100%
ExplanationAn ideal transformer is perfectly efficient, transferring all power without losses.
#17
What is the phenomenon where a material allows the flow of electrical current with little resistance called?
Conduction
ExplanationConduction is the movement of electrical charge through a material with minimal resistance.