Overvoltage Protection: Lightning Arresters, Surge Suppressors, and Insulation Coordination

Question 1

What is the primary function of a lightning arrester in an electrical power system?

Accepted Answer

To provide a low-impedance path for lightning current to flow to ground

Answer

To isolate a circuit during a fault

Answer

To regulate the voltage in a circuit

Answer

To prevent overloads

Question 2

What is the intended purpose of a surge suppressor?

Accepted Answer

To limit the voltage across a circuit during transient overvoltages

Answer

To protect equipment from overcurrents

Answer

To enhance the power factor of a system

Answer

To regulate the frequency of a circuit

Question 3

Which of the following is a common type of surge suppressor?

Accepted Answer

Metal oxide varistor (MOV)

Answer

Capacitor

Answer

Inductor

Answer

Transformer

Question 4

What primary factor influences the insulating strength of a material?

Accepted Answer

Material composition

Answer

Thickness

Answer

Temperature

Answer

Humidity

Question 5

What is the function of a grading ring on a lightning arrester?

Accepted Answer

To distribute voltage stress along the insulator

Answer

To prevent flashover

Answer

To enhance the insulation strength of the arrester

Answer

To reduce the overall size of the arrester

Question 6

What is the main purpose of a surge suppressor in an electrical power system?

Accepted Answer

To absorb and dissipate transient overvoltages

Answer

To provide a conductive path for lightning strikes to the ground

Answer

To isolate sensitive equipment from power surges

Answer

To regulate voltage levels within a specified range

Question 7

What is the primary goal of insulation coordination in an electrical power system?

Accepted Answer

To ensure that insulation can withstand voltage stresses without failure

Answer

To prevent electrical arcing between conductors

Answer

To minimize power losses due to corona discharge

Answer

To reduce the risk of electrical shock to personnel

Question 8

Which type of dielectric test is commonly used to verify the insulation resistance of a high-voltage transformer?

Accepted Answer

Megger test

Answer

Hipot test

Answer

Partial discharge test

Answer

Tan delta test

Question 9

Which of the following is not considered a type of overvoltage protection device?

Accepted Answer

Capacitor bank

Answer

Lightning arrester

Answer

Surge suppressor

Answer

Reactor

Question 10

Which characteristic is associated with metal-oxide varistors (MOVs)?

Accepted Answer

High energy absorption capacity

Answer

Low clamping voltage

Answer

Slow response time

Answer

High temperature stability

Question 11

What is the primary function of a gapless arrester?

Accepted Answer

To limit voltage surges by generating an arc

Answer

To absorb energy from voltage surges

Answer

To prevent power outages caused by lightning strikes

Answer

To isolate sensitive equipment from ground faults

Question 12

Which of the following is NOT specifically designed for overvoltage protection?

Accepted Answer

Capacitor bank

Answer

Lightning arrester

Answer

Surge suppressor

Answer

Metal oxide varistor (MOV)

Question 13

Which of the following is the primary function of a lightning arrester?

Accepted Answer

To protect equipment from overvoltages.

Answer

To interrupt fault currents.

Answer

To isolate faulty sections of a circuit.

Answer

To provide a ground path for lightning strikes only.

Question 14

Which of the following is a common type of overvoltage caused by switching operations?

Accepted Answer

Transient overvoltage

Answer

Lightning surge

Answer

Power frequency overvoltage

Answer

Harmonic overvoltage only.

Question 15

What is the purpose of a grounding grid in an electrical power system?

Accepted Answer

To provide a low-impedance path for fault currents.

Answer

To protect personnel from electrical shock only.

Answer

To reduce electromagnetic interference only.

Answer

To improve the voltage regulation of the system only.

Question 16

What is the primary purpose of a transient voltage surge suppressor (TVSS)?

Accepted Answer

To limit the voltage across sensitive electronic devices.

Answer

To provide a pathway for fault currents only.

Answer

To absorb excess energy from transients only.

Answer

To improve the power factor of the system only.

Question 17

What is the primary goal of insulation coordination in an electrical power system?

Accepted Answer

To guarantee the insulation strength of equipment exceeds the maximum voltage that can occur in the system.

Answer

To eliminate electrical arcs and short circuits.

Answer

To reduce power losses caused by leakage current.

Answer

To enhance the overall efficiency of the system.

Question 18

Which type of surge arrester utilizes metal oxide varistors (MOVs) as its active component?

Accepted Answer

MOV arrester

Answer

Thyristor arrester

Answer

Gas-filled arrester

Answer

Nonlinear resistor arrester

Question 19

What is the primary advantage of a thyristor arrester compared to a MOV arrester?

Accepted Answer

Higher energy handling capacity

Answer

Faster response time

Answer

Lower cost

Answer

Increased voltage protection

Question 20

What is the main purpose of a grading ring on a high-voltage insulator?

Accepted Answer

To distribute electric fields more evenly, preventing voltage breakdown

Answer

To prevent corona discharge

Answer

To increase insulation resistance

Answer

To improve the mechanical strength of the insulator

Question 21

What is the main function of a lightning arrester in an electrical power system?

Accepted Answer

To protect equipment from lightning surges

Answer

To interrupt fault currents

Answer

To regulate system voltage

Answer

To isolate faulty sections of the circuit

Question 22

What is the primary objective of insulation coordination in electrical power systems?

Accepted Answer

To ensure that the electrical insulation of system components can withstand expected overvoltages.

Answer

To minimize the risk of electrical breakdowns and equipment damage.

Answer

To protect equipment from lightning strikes.

Answer

To reduce the cost of maintaining power systems.

Question 23

What is the primary material used in the construction of porcelain insulators for overhead power lines?

Accepted Answer

Ceramic

Answer

Glass

Answer

Polymer

Answer

Composite

Question 24

What is the main purpose of using corona rings on high-voltage insulators?

Accepted Answer

To reduce the electric field gradient around the insulator, preventing corona discharge.

Answer

To improve the overall insulation strength of the insulator.

Answer

To prevent flashovers caused by excessive voltage.

Answer

To increase the leakage current across the insulator.

Question 25

What is the main function of lightning arresters in an electrical power system?

Accepted Answer

To safeguard against voltage spikes caused by lightning strikes

Answer

To suppress transient voltage surges

Answer

To provide insulation against ground faults

Answer

To protect equipment against short circuits

Question 26

What is the intended purpose of grading rings on an overhead transmission line insulator?

Accepted Answer

To reduce electrical stress on the insulator surface

Answer

To increase insulation resistance

Answer

To prevent contamination-induced flashovers

Answer

To enhance the dielectric strength of the insulator

Question 27

Which test method measures the insulation resistance of a cable?

Accepted Answer

Megger test

Answer

Hipot test

Answer

Dielectric absorption test

Answer

Withstand voltage test

Question 28

What is the primary role of a surge arrester in protecting against transient overvoltages in a power system?

Accepted Answer

Diverting excess voltage to ground

Answer

Storing and releasing energy during overvoltages

Answer

Limiting current flow during overvoltages

Answer

Isolating protected equipment from the power source

Question 29

Which of the following is the primary function of a lightning arrester in an electrical power system?

Accepted Answer

Limit voltage surges caused by lightning strikes

Answer

Prevent insulation breakdown

Answer

Protect transformers from overcurrents

Answer

Regulate system voltage

Question 30

What is the main purpose of insulation coordination in an electrical power system?

Accepted Answer

Ensure insulation integrity amidst expected voltage stresses

Answer

Prevent short circuits among conductors

Answer

Minimize power loss

Answer

Enhance system reliability

Question 31

Which type of surge suppressor commonly finds application in electrical power systems?

Accepted Answer

Metal oxide varistor (MOV)

Answer

Capacitor bank

Answer

Inductor

Answer

Voltage regulator

Question 32

What is the purpose of dielectric testing in electrical power systems?

Accepted Answer

Verify electrical insulation integrity

Answer

Measure conductor capacitance

Answer

Determine cable current capacity

Answer

Locate electrical equipment faults

Question 33

What is the primary function of a grounding system in an electrical power system?

Accepted Answer

Provide a low-impedance path for fault currents

Answer

Prevent electric shock

Answer

Improve voltage regulation

Answer

Reduce electromagnetic interference

Question 34

What is the operating principle of a surge arrester with a spark gap?

Accepted Answer

Uses gas ionization to create a conductive path for transient currents

Answer

Conducts current when voltage exceeds a threshold

Answer

Provides a grounding path for voltage spikes

Answer

Measures electrical system voltage

Question 35

Which of the following is a primary function of lightning arresters in power systems?

Accepted Answer

Diverting surge currents safely to ground

Answer

Isolating faults from the system

Answer

Storing electrical energy

Answer

Regulating voltage levels

Question 36

What is the main purpose of surge suppressors in overvoltage protection schemes?

Accepted Answer

Limiting transient voltage spikes to safe levels for connected equipment

Answer

Creating a direct path to ground for fault currents

Answer

Absorbing excess electrical energy

Answer

Isolating equipment from ground faults

Question 37

Which of the following materials is commonly used as insulation in overvoltage protection devices due to its excellent dielectric properties?

Accepted Answer

Epoxy resin

Answer

Steel

Answer

Copper

Answer

Aluminum

Question 38

What is the primary objective of insulation coordination in overvoltage protection?

Accepted Answer

Ensuring that insulation levels are sufficient to withstand anticipated voltage stresses

Answer

Determining the dielectric strength of insulation

Answer

Connecting different types of insulation materials

Question 39

Which of the following tests is specifically designed to measure the dielectric strength of an electrical insulator?

Accepted Answer

Dielectric withstand test

Answer

Insulation resistance test

Answer

Surge test

Answer

Continuity test

Question 40

What is the primary advantage of employing a graded insulation system in overvoltage protection?

Accepted Answer

Distributing voltage stress uniformly across insulation layers to prevent premature breakdown

Answer

Increasing the overall insulation thickness

Answer

Reducing the risk of corona discharge

Question 41

In electrical power systems, what is a common application of surge suppressors?

Accepted Answer

Protecting sensitive electronic equipment from damaging voltage transients

Answer

Regulating voltage levels in distribution circuits

Answer

Isolating faults in high-voltage transmission lines

Question 42

What is the primary function of a grounding electrode in overvoltage protection systems?

Accepted Answer

Providing a low-resistance path for surge currents to dissipate safely into the earth

Answer

Isolating the system from lightning strikes

Answer

Storing electrical energy for later use

Question 43

Which of the following is not a type of overvoltage protection device?

Accepted Answer

Circuit breaker

Answer

Lightning arrester

Answer

Surge suppressor

Answer

Insulator

Question 44

What is the primary function of a lightning arrester?

Accepted Answer

Divert surge currents to ground

Answer

Isolate sections of the system

Answer

Provide overcurrent protection

Answer

Absorb excess voltage

Question 45

Which component is commonly used as a surge suppressor?

Accepted Answer

MOV

Answer

Capacitor

Answer

Inductor

Answer

Resistor

Question 46

What is the significance of insulation coordination in overvoltage protection?

Accepted Answer

Ensure insulation withstands overvoltages without breakdown

Answer

Provide isolation between different sections of the system

Answer

Limit the flow of surge currents

Question 47

Which method is commonly used for dielectric testing?

Accepted Answer

Hipot testing

Answer

Ohmmeter testing

Answer

Continuity testing

Answer

Insulation resistance testing

Question 48

What is the primary factor determining the voltage rating of a lightning arrester?

Accepted Answer

System voltage

Answer

Lightning current magnitude

Answer

Surge duration

Answer

Insulation level

Question 49

What is the purpose of grounding in an overvoltage protection system?

Accepted Answer

Provide a low-impedance path for surge currents

Answer

Isolate the system from the ground

Answer

Absorb excess voltage

Question 50

Which outcome is not associated with overvoltage events?

Accepted Answer

Improved system reliability

Answer

Loss of data

Answer

Damage to equipment

Answer

Electrical fires