1.
What is the unit of resistance?
Correct Answer
A. Ohms
Explanation
The unit of resistance is Ohms. Ohms is a measure of how much an object resists the flow of electric current. It is named after the German physicist Georg Simon Ohm, who formulated Ohm's Law, which describes the relationship between current, voltage, and resistance in an electrical circuit. Amps is the unit of electric current, volts is the unit of electric potential difference, and Hertz is the unit of frequency.
2.
When you increase the voltage of a wave, it gets sharper.
Correct Answer
B. False
Explanation
Increasing the voltage of a wave does not make it sharper. The sharpness of a wave is determined by its frequency, not its voltage. Voltage refers to the potential difference between two points in a circuit, while the frequency of a wave is the number of complete cycles it completes in a given time period. Therefore, changing the voltage does not affect the sharpness of a wave.
3.
Water is a bad conductor of electricity.
Correct Answer
B. False
Explanation
Water is actually a good conductor of electricity. It contains ions, such as sodium and chloride, which can carry electric charge. When dissolved in water, these ions allow for the flow of electric current. However, pure water, without any impurities or dissolved ions, is a poor conductor of electricity. So, the statement that water is a bad conductor of electricity is false.
4.
The color of the live core of a cable is
Correct Answer
A. Brown
Explanation
The color of the live core of a cable is brown. This is based on the standard color coding system used in electrical wiring. In this system, brown is typically used to indicate the live or active wire in a cable. The live wire carries the current from the power source to the device or appliance being powered. Therefore, if you encounter a cable with a brown core, it is important to treat it as live and take necessary precautions when working with it.
5.
………………………… is generated from different sources such as power stations.
Correct Answer
B. Electricity
Explanation
Electricity is generated from different sources such as power stations. These power stations convert various forms of energy, such as chemical, nuclear, or renewable energy, into electrical energy. This electrical energy can then be transmitted through power lines to homes, businesses, and other places where it is used to power appliances, lighting, and other electrical devices. Therefore, electricity is the correct answer as it is the form of energy that is generated from different sources, including power stations.
6.
To prevent accidents and injuries in the workshop, you must follow the ………………………… rules and practices.
Correct Answer
A. Safety
Explanation
Following safety rules and practices is essential to prevent accidents and injuries in the workshop. This includes using appropriate personal protective equipment, adhering to proper operational procedures, and maintaining a clean and organized workspace. Safety protocols are designed to minimize risk and ensure a safe working environment for everyone.
7.
An example of a good ………………………… is wood.
Correct Answer
D. Insulator
Explanation
Wood is a good example of an insulator because it does not allow electricity or heat to easily pass through it. It has high resistance to the flow of electric current, making it a poor conductor. Wood is commonly used as an insulating material in various applications, such as electrical wiring, to prevent the risk of electrical shocks or short circuits.
8.
A ………………………… is a variable resistor that allows resistance value to change with the light.
Correct Answer
C. LDR
Explanation
An LDR (Light Dependent Resistor) is a variable resistor that allows the resistance value to change with the light. It is made of a semiconductor material that exhibits a decrease in resistance as the intensity of light increases. This property makes it useful in various applications such as automatic street lights, camera exposure control, and solar panels. Unlike a regular resistor or a bulb, an LDR specifically reacts to changes in light levels, making it the correct answer in this context.
9.
An electrical shock is received when ………………………… passes through the body.
Correct Answer
C. Electric current
Explanation
An electrical shock is received when electric current passes through the body. Electric current refers to the flow of electric charge in a circuit. When a person comes into contact with a live wire or an electrical source, the electric current can pass through their body, causing an electrical shock. This can result in various injuries or even be fatal, depending on the intensity of the current and the duration of the exposure. Therefore, electric current is the correct answer in this case.
10.
It is safe to use electrical appliances in a wet area.
Correct Answer
B. False
Explanation
It is not safe to use electrical appliances in a wet area because water is a conductor of electricity. When electrical appliances come into contact with water, it increases the risk of electric shock or short circuits, which can lead to injuries or even fatalities. It is important to keep electrical appliances away from water sources and ensure that they are used in dry conditions to prevent any accidents or electrical hazards.
11.
The component inside a 3-pin plug is called a fuse.
Correct Answer
A. True
Explanation
The component inside a 3-pin plug that is responsible for protecting the electrical circuit from overloading or short-circuiting is called a fuse. A fuse is designed to melt and break the circuit if excessive current flows through it, preventing damage to the electrical devices and the wiring. Therefore, the statement "The component inside a 3-pin plug is called a fuse" is true.
12.
Wire crimpers are used to connect two wires together.
Correct Answer
A. True
Explanation
Wire crimpers are a type of tool that is specifically designed to connect two wires together. They work by compressing a metal sleeve or "crimp" onto the wires, creating a secure and reliable electrical connection. This process is commonly used in various industries and applications where a strong and durable wire connection is required. Therefore, the statement that wire crimpers are used to connect two wires together is true.
13.
Conductors are materials that do not allow current to flow.
Correct Answer
B. False
Explanation
Conductors are materials that allow current to flow easily. They have low resistance and are characterized by the presence of free electrons that can move through the material. Examples of conductors include metals like copper and aluminum. Therefore, the statement "Conductors are materials that do not allow current to flow" is incorrect.
14.
The function of an inductor is to store electric charge.
Correct Answer
B. False
Explanation
The function of an inductor is not to store electric charge. Instead, an inductor stores energy in the form of a magnetic field when an electric current passes through it. When the current changes, the magnetic field collapses, and the stored energy is released. Therefore, inductors are used to control the flow of current in a circuit and to store energy in a magnetic field, not electric charge.
15.
Capacitors are specified by three quantities; capacitor value, tolerance, and voltage rating.
Correct Answer
A. True
Explanation
Capacitors are indeed specified by three quantities: capacitor value, tolerance, and voltage rating. The capacitor value represents the amount of charge it can store, the tolerance indicates the acceptable range of variation in the capacitor's value, and the voltage rating indicates the maximum voltage that the capacitor can handle without breaking down. Therefore, the statement is true.
16.
A diode has two terminals called anode and cathode.
Correct Answer
A. True
Explanation
A diode is a two-terminal electronic component that allows current to flow in only one direction. The anode is the positive terminal, while the cathode is the negative terminal. This is because the diode is designed to have a specific polarity, and the anode must be connected to the higher voltage side of the circuit for it to function properly. Therefore, the statement that a diode has two terminals called anode and cathode is true.
17.
Variable resistors can be used to adjust motor speeds.
Correct Answer
A. True
Explanation
Variable resistors, also known as potentiometers, are electrical components that can be adjusted to change the resistance in a circuit. By altering the resistance, the amount of current flowing through the circuit can be controlled. In the case of motor speeds, variable resistors can be used to adjust the voltage or current supplied to the motor, thereby regulating its speed. This makes the statement "Variable resistors can be used to adjust motor speeds" true.
18.
This sign means Highly Flammable.
Correct Answer
B. False
Explanation
This sign does not mean "Highly Flammable." The given sign is not provided, so it is impossible to determine its meaning. Therefore, the correct answer is False.
19.
To clean the tip of the soldering iron, use...
Correct Answer
D. A wet sponge
Explanation
A wet sponge is the correct answer because it is the most effective tool for cleaning the tip of a soldering iron. When the tip of the iron is heated, flux and solder residue can build up, which can affect the quality of the solder joint. Using a wet sponge helps to remove this residue by providing a damp surface to wipe the tip against. The moisture in the sponge helps to cool down the tip quickly, preventing damage to the soldering iron and ensuring that it is clean and ready for use.
20.
The first stage in PCB fabrication is
Correct Answer
A. Preparing the artwork
Explanation
The first stage in PCB fabrication is preparing the artwork. This involves creating a design or layout of the printed circuit board, including the placement of components and the routing of traces. The artwork serves as a blueprint for the fabrication process, guiding the subsequent steps such as exposure, developing, rinsing, and tinning. It is crucial to have a well-prepared artwork to ensure the accurate and precise production of the PCB.
21.
Recognize it.
Correct Answer
C. PCB cutter
Explanation
The given options are Edge rounder, PCB mega station, PCB cutter, and UV exposure unit. Out of these options, the correct answer is PCB cutter. This device is specifically designed for cutting printed circuit boards (PCBs) accurately and precisely. It is used to separate individual PCBs from a larger panel or sheet. The other options mentioned are not meant for cutting PCBs but serve different purposes in the PCB manufacturing process.
22.
Recognize it.
Correct Answer
D. LED
Explanation
The correct answer is LED because a LED, or Light Emitting Diode, is a type of diode that emits light when an electric current is applied to it. It is commonly used in electronic devices as an indicator light or for displaying information. The other options, such as a LDR (Light Dependent Resistor) or a capacitor, do not emit light and therefore do not fit the description given in the question.
23.
An oscilloscope is a device that is used to generate different waveforms.
Correct Answer
B. False
Explanation
An oscilloscope is not used to generate different waveforms. Instead, it is a device used to display and analyze waveforms that have already been generated by other sources. It is commonly used in electronics and telecommunications to measure and observe electrical signals.
24.
The edge rounder is equipment used to drill holes on the PCB.
Correct Answer
B. False
Explanation
The given statement is false. The edge rounder is not used to drill holes on the PCB. The edge rounder is a machine used to smoothen the edges of the PCB by removing sharp corners and creating a rounded edge. It is not involved in the process of drilling holes on the PCB, which is typically done using a drilling machine or a CNC drilling machine.
25.
Developing and rinsing is the last stage in PCB fabrication.
Correct Answer
B. False
Explanation
The given statement is false. Developing and rinsing is not the last stage in PCB fabrication. After developing and rinsing, the next stages in PCB fabrication typically include etching, drilling, solder mask application, and final inspection. These stages are crucial for the completion of the PCB fabrication process.
26.
It is not possible to measure voltage values across resistances in a circuit using a function generator.
Correct Answer
A. True
Explanation
A function generator is a device that generates electrical waveforms, typically in the form of a sine wave, square wave, or triangle wave. It is primarily used for testing and troubleshooting electronic circuits. However, a function generator is not designed to measure voltage values across resistances in a circuit. It is used to generate signals, not to measure them. Therefore, it is not possible to directly measure voltage values across resistances using a function generator. Hence, the answer is true.
27.
Solder wire is an alloy made up of tin and lead.
Correct Answer
A. True
Explanation
Solder wire is indeed an alloy made up of tin and lead. This combination creates a low-melting point material that is commonly used to join or bond metal surfaces together. The tin provides the main component of the alloy, while the lead helps to lower the melting point and improve the flow characteristics of the solder. This makes it easier to work with and ensures a strong bond when soldering electronic components or other metal objects.
28.
The function of a capacitor is to store electric charge.
Correct Answer
A. True
Explanation
A capacitor is an electronic component that stores electric charge. When a voltage is applied to a capacitor, it accumulates and stores electrical energy in an electric field. This stored charge can be released later on when the capacitor is connected to a circuit. Therefore, the statement "The function of a capacitor is to store electric charge" is true. Capacitors are commonly used in electronic circuits for various purposes such as energy storage, filtering, and timing.
29.
The process shown below is called...
Correct Answer
B. Desoldering
Explanation
The process shown in the image is called desoldering. Desoldering is the process of removing solder from a joint or component in order to replace or repair it. It is typically done using a desoldering pump or a desoldering wick to heat the solder and then remove it. This process allows for the removal of faulty or damaged components without causing further damage to the surrounding circuitry.
30.
The pressure that causes the flow of electric current is
Correct Answer
B. Voltage
Explanation
Voltage is the correct answer because it is the driving force that causes the flow of electric current. Voltage, also known as electric potential difference, creates an imbalance of charge that pushes electrons through a conductor, resulting in the flow of current. Without voltage, there would be no movement of electric charges and no current. Resistance and power are related to current flow but do not directly cause it.