1.
Electric Shock occurs when a person becomes part of the
Correct Answer
A. Circuit
Explanation
Electric shock occurs when a person becomes part of an electrical circuit. This typically happens when the person comes into contact with both a source of electricity and the ground, thereby completing the circuit and allowing electrical current to pass through the body. This can result in injury or even fatality, depending on the voltage and other factors.
2.
All exposed metal in the electrical circuit should be
Correct Answer
A. Earthed
Explanation
In an electrical circuit, it is important to earth or ground all exposed metal. This is done to provide a safe path for electric current in case of a fault or short circuit. By connecting the metal to the earth, any excess current will flow harmlessly into the ground instead of causing damage or posing a risk to people. This helps to prevent electrical shocks, fires, and other hazards that could occur if the metal was not properly earthed.
3.
Before working on a circuit, you must ........................... the power supply.
Correct Answer
B. Switch off
Explanation
Before working on a circuit, it is necessary to switch off the power supply. This is important to ensure safety and prevent any electrical accidents or damage. By switching off the power supply, you are cutting off the flow of electricity and reducing the risk of electric shock or short circuits. It allows you to work on the circuit without any power running through it, minimizing the chances of getting injured or causing any damage to the components.
4.
The accepted lethal level of shock current passing through a person is about
Correct Answer
C. 30mA
Explanation
The generally accepted lethal level of electrical shock current passing through a human body is about 30 milliamperes (mA). This level of current, particularly when passing through the heart, can be fatal due to its ability to disrupt the electrical signals that manage the heartbeat, potentially leading to cardiac arrest. Safety devices like Ground Fault Circuit Interrupters (GFCIs) are designed to trip and cut off the power if a current as low as 5mA to 6mA is detected leaking, well below the lethal threshold, to provide an additional margin of safety.
5.
Electricity is made at a power plant by a huge.
Correct Answer
B. Generator
Explanation
Electricity is made at a power plant by a generator. A generator is a device that converts mechanical energy into electrical energy. It consists of a rotating coil of wire called an armature, which is connected to a source of mechanical energy such as a motor. As the armature rotates within a magnetic field, it induces a flow of electrons, generating electricity. Therefore, a generator is the correct answer for how electricity is made at a power plant.
6.
To prevent accidents and injuries in the workshop, you must understand and follow safety rules.
Correct Answer
A. True
Explanation
Following safety rules is crucial in preventing accidents and injuries in a workshop. By understanding and adhering to these rules, individuals can minimize risks and create a safer working environment. This includes wearing appropriate protective gear, using equipment correctly, maintaining a clean and organized workspace, and being aware of potential hazards. By prioritizing safety, individuals can reduce the likelihood of accidents and ensure the well-being of themselves and others in the workshop.
7.
The severity of an electric shock depends more on the voltage when compared to the current.
Correct Answer
B. False
Explanation
The severity of an electric shock depends more on the current rather than the voltage. While voltage determines the potential for electric shock, it is the current that actually flows through the body and causes harm. Even a low voltage can be dangerous if there is a high current flow. Therefore, the statement that the severity of an electric shock depends more on the voltage is false.
8.
Mandatory signs are used to indicate that a specific course of action must be taken.
Correct Answer
A. True
Explanation
Mandatory signs are indeed used to indicate that a specific course of action must be taken. These signs are typically in the form of a white symbol or word on a blue background, and they are used to convey instructions or requirements that drivers or pedestrians must follow. Ignoring or disobeying these signs can result in penalties or hazards, making it important for individuals to adhere to the indicated actions.
9.
Green/Yellow wire is always considered as part of the live circuit.
Correct Answer
B. False
Explanation
The given statement is false. Green/Yellow wire is not always considered as part of the live circuit. In electrical wiring, the green/yellow wire is typically used as the protective earth wire or ground wire. It is used to provide a safe path for electrical current to flow in case of a fault or short circuit, and it is not intended to carry the live current. The live circuit is usually carried by wires of different colors, such as black or brown.
10.
Fuse is used to protect the circuit against earth leakage current.
Correct Answer
B. False
Explanation
Fuses are not used to protect the circuit against earth leakage current. Instead, they are used to protect the circuit against excessive current flow. Earth leakage current is typically protected by devices such as residual current devices (RCDs) or ground fault circuit interrupters (GFCIs).
11.
RCD stands for the residual current devices.
Correct Answer
A. True
Explanation
RCD stands for Residual Current Devices, which are electrical safety devices designed to protect against electric shock and fire hazards. They work by monitoring the flow of electric current and quickly shutting off the power if a leakage or imbalance is detected. This helps to prevent potentially dangerous situations and provides an additional layer of protection in electrical circuits. Therefore, the statement "RCD stands for the residual current devices" is true.
12.
Pin number 2 is connected to
Correct Answer
B. Live
Explanation
Pin number 2 is connected to the Live wire. In electrical systems, the Live wire carries the current from the power source to the device, while the Neutral wire completes the circuit. The Earth wire is used for safety purposes to prevent electric shocks. The Fuse is a protective device that interrupts the flow of current in case of an overload or short circuit. Therefore, based on the given options, the correct answer is Live.
13.
Pin number 4 of the plug is connected to
Correct Answer
A. Earth
Explanation
Pin number 4 of the plug is connected to Earth. The Earth pin is responsible for grounding the electrical appliance and providing a safe path for any excess electrical current to flow into the ground. This is crucial for preventing electrical shocks and ensuring the safety of the user. The Earth pin in electrical plugs and outlets serves two main purposes:
Grounding: It connects the appliance to the ground, stabilizing voltage and preventing electrical surges.
Safety: It provides a safe path for excess electrical current to flow into the ground, reducing the risk of electrical shocks and protecting users and devices.
14.
What is the function of the shaft in a screwdriver?
Correct Answer
B. To connect the head and handle
Explanation
The shaft in a screwdriver serves the purpose of connecting the head, which interacts with the screws, to the handle that provides the user with a grip. It ensures the efficient transmission of rotational force while using the tool.
15.
The sign shown in the picture is
Correct Answer
B. Advisory
Explanation
The sign shown in the picture is likely an advisory sign. Advisory signs are used to provide guidance or suggestions to drivers about potential hazards or conditions on the road ahead. They are usually diamond-shaped with a yellow background and black symbols or text. These signs are not mandatory, but they inform drivers about specific situations or actions they should consider taking while driving.
16.
The meter shown in the picture is
Correct Answer
C. Power meter
Explanation
The meter shown in the picture is a power meter. This can be determined by analyzing the design and features of the meter, such as the presence of power measurement symbols, wattage units, and other indicators commonly found in power meters. A power meter is used to measure the electrical power consumption or generation of a device or circuit, making it the most suitable option among the given choices.
17.
Overload currents occur when
Correct Answer
D. All of the above
Explanation
Overload currents occur when equipment is overloaded, meaning it is being used beyond its capacity or rated limits. They can also occur when the installation is abused, for example, by using equipment in a way it was not intended or by subjecting it to excessive stress or misuse. Additionally, overload currents can be caused by a badly designed installation, where the electrical system is not properly designed or sized to handle the load requirements. Therefore, all of the given options contribute to the occurrence of overload currents.
18.
The shown below figure is called
Correct Answer
A. Consumer unit
Explanation
The figure shown below is called a consumer unit. A consumer unit is an electrical distribution board that controls and distributes electricity throughout a building or premises. It contains various components such as MCBs (Miniature Circuit Breakers) which protect individual circuits from overloading or short circuits, RCDs (Residual Current Devices) which provide protection against electric shocks, and LCDs (Liquid Crystal Displays) which may be used for displaying information such as power consumption or fault indicators. The consumer unit is an essential part of the electrical system in a building, ensuring safety and proper distribution of electricity.
19.
The difference between a FUSE and a Circuit Breaker (CB)
Correct Answer
B. Fuse can be used only once, but CB can be used many times.
Explanation
The correct answer is "Fuse only once and, but CB many times". This means that a fuse can only be used once and needs to be replaced after it blows, while a circuit breaker can be used multiple times as it can be reset after tripping.
20.
One of the devices is not used for protection.
Correct Answer
D. Socket
Explanation
The RCD (Residual Current Device), MCB (Miniature Circuit Breaker), and Fuse are all devices used for protection in electrical circuits. They help to prevent electrical hazards such as short circuits and electrical fires. However, a socket is not typically used for protection but rather for providing an outlet for electrical devices to be plugged into. Therefore, the socket is the device in the given list that is not used for protection.
21.
Which component is used to manually control the opening and closing of an electrical circuit?
Correct Answer
B. Switch
Explanation
A switch is an electrical component that manually opens or closes an electrical circuit, allowing current to flow or stop flowing through the circuit. This control is essential in everyday devices like lights and appliances, where it enables the user to turn power on and off at will. Switches are fundamental components in household and industrial electrical systems, offering simple, effective control over electrical power.
22.
What does the term 'IP rating' refer to in electrical installations?
Correct Answer
C. Ingress Protection rating, indicating the level of sealing effectiveness of electrical enclosures against intrusions
Explanation
The 'IP rating' in electrical installations refers to the Ingress Protection rating system, which classifies and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion from different foreign bodies (tools, dirt, etc.) and moisture. This rating system helps in determining how well an enclosure protects the internal components of electrical devices from external elements, which is critical for ensuring durability and safety in various environmental conditions.
23.
What is the purpose of a cable gland in electrical installations?
Correct Answer
A. To securely attach and seal the cable to the equipment
Explanation
A cable gland is used in electrical installations to securely attach and seal the end of a cable to the equipment. This device provides strain relief and connects the cable, enclosure, or conduit in a way that maintains the integrity of the sealing and provides necessary environmental protection. It ensures that electrical connections remain tight and protected from dust, moisture, and mechanical stress, which are crucial for maintaining safety and functionality in electrical systems.