An electric shock occurs when electric current flows through the body, potentially causing injury or death depending on the current intensity. The severity depends on the amount of current, the duration, and the path it takes through the body.
Which is the primary safety device in an electrical circuit?
A Circuit breaker
B Voltmeter
C Ammeter
D Capacitor
A circuit breaker is the primary safety device in electrical circuits. It automatically disconnects the circuit if there is an overload or short circuit, preventing damage to electrical components and reducing the risk of fires or shocks.
What is the purpose of electrical standards?
A Reduce power consumption
B Increase current flow
C Measure voltage
D Ensure safety and reliability
Electrical standards provide guidelines and rules for designing, constructing, and operating electrical systems. They ensure safety, reliability, and efficiency, protecting both people and equipment from electrical hazards and malfunctions.
What should you do when troubleshooting a circuit with no power?
A Disconnect the switch
B Check the fuse
C Replace the battery
D Increase the voltage
When troubleshooting a circuit with no power, the first step is to check the fuse. A blown fuse is a common cause of power loss, as it disconnects the circuit to prevent damage from an overload.
What is the most common cause of electrical fires?
A Poor insulation
B High voltage
C Overloaded circuits
D Low current
Overloaded circuits are the most common cause of electrical fires. When too many devices draw power from a single circuit, the wires heat up, and if not properly protected, can cause a fire hazard.
What should you check first if an appliance does not turn on?
A Power cord
B Battery
C Plug socket
D Light bulb
When an appliance doesn’t turn on, the first thing to check is the power cord. A frayed or damaged cord can interrupt power flow, preventing the appliance from functioning. Inspect for visible damage and try another outlet.
What is the function of a grounding system in electrical safety?
A Increase current flow
B Prevent electrical shock
C Protect from voltage spikes
D Increase power
The grounding system provides a safe path for excess electricity to flow into the earth, preventing electrical shock. It helps protect people and electrical devices from faults like short circuits by ensuring that any stray current is safely dissipated.
What should you do if you experience an electric shock?
A Touch the source of shock
B Stand up and walk
C Turn off the switch
D Break contact with the power source
If you experience an electric shock, the first action should be to break contact with the power source. This can be done by turning off the switch or using a non-conductive object to push the person away from the source.
What does a GFCI (Ground Fault Circuit Interrupter) do?
A Detects ground faults and cuts power
B Measures voltage
C Provides current regulation
D Increases power efficiency
A GFCI is a safety device that detects ground faults—unintended paths of current—and quickly cuts off power to prevent electrical shock. GFCIs are commonly used in areas with high moisture, such as kitchens and bathrooms.
What is the primary cause of an electrical circuit overload?
A Low voltage
B Short circuit
C Using too many appliances
D High resistance
Circuit overloads occur when too many appliances are connected to a single circuit, drawing more current than it can handle. This can lead to overheating, and if unprotected, may result in electrical fires or damaged components.
What does the symbol of a resistor in an electrical diagram look like?
A A circle
B A triangle
C A straight line
D A zig-zag line
The symbol of a resistor in an electrical diagram is represented by a zig-zag line. This indicates a component that resists the flow of electric current, converting electrical energy into heat.
What is the function of a fuse in an electrical circuit?
A Protect components from heat
B Prevent overcurrent
C Control current flow
D Measure voltage
A fuse is a safety device designed to prevent overcurrent. It contains a metal wire that melts when excessive current flows, breaking the circuit and preventing further damage to the system or connected components.
What is the unit of electrical power?
A Watt
B Volt
C Ampere
D Ohm
Watt (W) is the unit of electrical power, representing the rate at which electrical energy is consumed or produced. It is the product of voltage (V) and current (I) in a circuit.
How does an electric meter measure power consumption?
A By frequency
B By voltage
C By energy used over time
D By current
An electric meter measures power consumption by calculating the energy used over time. It tracks the total amount of electrical energy (in kilowatt-hours) consumed by the household or facility.
What does the symbol of a battery look like in an electrical diagram?
A A square
B Two long lines of unequal length
C A circle with a cross
D A rectangle
In an electrical diagram, a battery is represented by two long lines of unequal length, with the longer line representing the positive terminal and the shorter one representing the negative terminal. This symbol indicates a DC power source.