Samacheer Kalvi Class 6 Science Solutions Term 2 Chapter 2 Electricity

Question 3. Write short notes on conductors and insulators.
Answer:
Conductors:
Conductors are materials that allow electric charges to move through them easily. The rate of flow of these charges in a circuit is called electric current. Materials that permit this flow are known as conductors. For instance, copper, iron, aluminum, impure water, and the Earth itself are good examples of conductors. These materials are used to make wires and other electrical components.

Insulators (Non-Conductors):
Insulators, also known as non-conductors, are materials that do not allow electric charges to pass through them easily. They have a very high resistance to the flow of electricity. Examples include plastic, glass, wood, rubber, china clay, and ebonite. Insulators are used to protect us from electric shock and to prevent short circuits by covering conducting wires.
In simple words: Conductors are materials that let electricity pass through them, like metals such as copper. Insulators are materials that block electricity from passing through, like plastic or wood. Conductors are used in wires, and insulators are used for safety covers.

🎯 Exam Tip: Remember that conductors have free electrons that can move easily, while insulators have tightly bound electrons, preventing easy flow of current.

IX. Questions Based on Higher Order Thinking Skills

Question 1. Rahul wants to make an electric circuit. He has a bulb, two wires, a safety pin, and a piece of copper. He does not have any electric cell or battery. Suddenly he gets some idea. He uses lemon instead of a battery and makes a circuit. Will the bulb glow?
Answer:
1. Yes, the bulb will glow.
2. Rahul can create a simple electric cell using the lemon. He needs to insert a piece of copper (like the copper wire) on one side of the lemon, which will act as the positive terminal. He can then insert a safety pin (made of a different metal, like zinc or iron) on the other side, which will act as the negative terminal. The acidic lemon juice serves as the electrolyte.
3. When the copper rod (positive terminal) and safety pin (negative terminal) are connected to the electric bulb using the connecting wires, a chemical reaction occurs in the lemon. This reaction generates a small electric current.
4. This current will then flow through the circuit and make the bulb glow, demonstrating how a basic battery works using natural materials.

In simple words: Yes, the bulb will light up. Rahul can use a lemon as a simple battery by sticking a copper piece and a safety pin into it. The lemon juice helps to make a small electric flow, which will light the bulb.

🎯 Exam Tip: This question tests your understanding of basic electrochemical cells and how different metals immersed in an electrolyte can generate an electric current.

X. Search Ten Words in the Given Word Grid and Classify Them as Conductors and Insulators

Question 1. Search ten words in the given word grid and classify them as conductors and insulators.

🎯 Exam Tip: Practice identifying materials as conductors or insulators based on their properties to classify them correctly.

Samacheer Kalvi 6th Science Electricity Additional Important Questions and Answers

I. Choose the Right Answer:

Question 1. Here heat energy is converted into electric energy
(a) Thermal power station
(b) Atomic power station
(c) Hydel power station
(d) Windmills
Answer: (a) Thermal power station
In simple words: Thermal power stations burn fuel to make heat, which then turns into electricity. This is a common way to generate power.

🎯 Exam Tip: Remember that "thermal" refers to heat, which is the primary energy conversion in thermal power stations.

Question 2. In atomic power station, ________ is used to rotate the turbine.
(a) water
(b) steam
(c) Air
(d) diesel
Answer: (b) steam
In simple words: Atomic power stations use the heat from nuclear reactions to create steam, which then spins the turbines to make electricity. Steam is key in this process.

🎯 Exam Tip: Most large-scale power generation methods (thermal, atomic) convert an initial energy source into heat, which then produces steam to drive turbines.

Question 3. Which one of the following is using secondary using cells?
(a) Hand watch
(b) Robo toy
(c) Laptop
(d) None of the options
Answer: (c) Laptop
In simple words: Laptops use secondary cells because these types of cells can be recharged many times. This means you don't have to throw them away after one use.

🎯 Exam Tip: Secondary cells are rechargeable, making them suitable for devices that require frequent power replenishment like laptops and mobile phones.

Question 4. If two or more ________ are connected in series in a circuit, then it is called a series circuit.
(a) keys
(b) cells
(c) connecting wires
(d) bulbs
Answer: (d) bulbs
In simple words: When you connect two or more bulbs one after another in a circuit, it forms a series circuit. All the bulbs share the same path for electricity.

🎯 Exam Tip: In a series circuit, all components are connected end-to-end, forming a single path for the current to flow.

Question 5. ........... fish is able to produce an electric current.
(a) Goldfish
(b) Electric Eel
(c) Katla
(d) Salamon fish
Answer: (b) Electric Eel
In simple words: The Electric Eel is a special type of fish that can create its own electricity. It uses this electricity to stun prey or defend itself.

🎯 Exam Tip: Remember specific examples of animals that generate electricity, as they are common knowledge questions.

II. Fill In The Blanks:

Question 1. Any device from which electricity is produced is called ...........
Answer: Source of electricity
In simple words: The origin of electric power for anything is called a source of electricity. For example, a power station or a battery.

🎯 Exam Tip: Knowing fundamental definitions like "source of electricity" is crucial for basic science questions.

Question 2. The place in Kanyakumari district that has more windmills is ...........
Answer: Aralvaimozhi
In simple words: Aralvaimozhi in Kanyakumari is a famous place known for having many windmills that generate power. The strong winds there make it a perfect spot.

🎯 Exam Tip: When learning about renewable energy, remember the names of specific locations known for power generation, especially within your region.

Question 3. ........... have long economic lives and low operating cost.
Answer: Hydel power stations
In simple words: Hydel power stations, which use water to make electricity, are good because they last a long time and don't cost much to run daily. This makes them very efficient for generating power.

🎯 Exam Tip: Understand the advantages of different power station types, focusing on their lifespan and operational costs.

Question 4. A chemical solution that produces positive and negative ions is used as ...........
Answer: electrolyte
In simple words: An electrolyte is a liquid, often a chemical solution, that helps electricity flow by creating charged particles called ions. This is how batteries work.

🎯 Exam Tip: Define key scientific terms precisely; an electrolyte is essential for understanding how cells and batteries function.

Question 5. ........... invented the electric bulb.
Answer: Thomas Alva Edison
In simple words: Thomas Alva Edison is widely recognized for inventing the practical and long-lasting electric light bulb. His work changed how people lit their homes and cities.

🎯 Exam Tip: Remember important inventors and their contributions, especially for foundational technologies like the electric bulb.

III. True Or False. If False, Give The Correct Answer.

Question 1. In a parallel circuit, the electricity has more than one path.
Answer: True
In simple words: In a parallel circuit, electricity can travel through several different routes to complete its path. This is unlike a series circuit, where there is only one path.

🎯 Exam Tip: Clearly understand the difference between parallel and series circuits, especially regarding current paths.

Question 2. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell.
Answer: False - The negative terminal of one cell is connected to the positive terminal of the other cell.
In simple words: To join two cells to make a battery, you connect the positive end of one cell to the negative end of the next cell. This creates a longer circuit with more power.

🎯 Exam Tip: Remember the correct way to connect cells in a series: positive to negative to ensure proper voltage addition.

Question 3. The switch is used to close or open an electric circuit.
Answer: True
In simple words: A switch acts like a gate in an electric circuit; it either allows the electricity to flow (closes the circuit) or stops it (opens the circuit). This controls devices.

🎯 Exam Tip: Know the function of common circuit components, such as a switch for controlling current flow.

Question 4. Pure water is a good conductor of electricity.
Answer: False - Pure water is an insulator.
In simple words: Pure water does not let electricity pass through it easily; it acts like a block. It's the impurities in water, like salt, that make it conductive.

🎯 Exam Tip: Distinguish between pure water (insulator) and impure water (conductor) regarding electrical conductivity.

Question 5. Secondary cell can be used only once.
Answer: False - Secondary cells can be used many times.
In simple words: Secondary cells are special batteries that you can charge up again and again after they run out of power. This makes them reusable and cost-effective.

🎯 Exam Tip: Understand the key difference between primary (single-use) and secondary (rechargeable) cells.

IV. Match The Following

Question 1. Match the following:

🎯 Exam Tip: To score full marks in matching questions, make sure to link each item in column A to its correct corresponding item in column B.

V. Assertion And Reason

Question 1. Assertion (A) : Experiments with electricity should only be performed with torch or radio batteries.
Reason (R) : Household electric supply will have high voltage and dangerous
(a) Both A and R are correct and R is the correct explanation for A.
(b) A is correct, but R is not the correct explanation for A.
(c) A is wrong but R is correct.
(d) Both A and R are correct and R is not the correct explanation
Answer: (a) Both A and R are correct and R is the correct explanation for A.
In simple words: It is safe to experiment with small batteries because household electricity is very strong and can be harmful. The reason directly explains why small batteries are safer.

🎯 Exam Tip: In assertion-reason questions, first check if both statements are true, then determine if the reason directly explains the assertion.

Question 2. Assertion (A) : Primary cells can not be recharged, they can be used only once.
Reason (R) : In vehicles, we use primary cells.
(a) Both A and R are correct and R is the correct reason for A.
(b) A is true but R is not correct.
(c) Both A and R are correct, but R is not the correct reason for A
(d) A is not correct but R is correct
Answer: (b) A is true but R is not correct.
In simple words: Primary cells are indeed one-time use batteries and cannot be recharged. However, most vehicles actually use rechargeable (secondary) cells, not primary cells. So the reason is wrong.

🎯 Exam Tip: Carefully evaluate the truthfulness of both the assertion and the reason, and then check if the reason logically supports the assertion.

VI. Very Short Answer:

Question 1. What are the places in which atomic power stations located in Tamil Nadu?
Answer:
1. Kalpakkam, Kanchipuram district.
2. Koodankulam, Tirunelveli district.
In simple words: Atomic power stations, which create electricity from nuclear energy, are found in two main places in Tamil Nadu: Kalpakkam and Koodankulam.

🎯 Exam Tip: Remember specific geographical locations for major power stations, as these are often tested knowledge points.

Question 2. List out the parts required to make an electric circuit
Answer: The parts needed to make a simple electric circuit are a key (switch), connecting wires, a dry cell or battery (power source), and an electric bulb (load). Each part plays a vital role in completing the circuit and allowing current to flow.
In simple words: You need a switch, wires, a battery, and a bulb to make a simple electric circuit.

🎯 Exam Tip: Be able to identify and list the four basic components essential for any functional electric circuit.

Question 3. How to connect the cells in torchlight to glow bulbs?
Answer: To make a bulb glow in a torchlight, connect the positive terminal of one cell to the negative terminal of another cell. This series connection ensures that the bulb gets enough voltage to light up. After correct connection, the bulb will glow.
In simple words: To make the bulb light up, connect the plus (+) end of one battery to the minus (-) end of the next battery.

🎯 Exam Tip: Understand how cells are connected in series (positive to negative) to increase voltage and power a device.

Question 4. How electric current is produced in Thermal power stations?
Answer: In thermal power stations, heat energy is created by burning coal. This heat turns water into steam. The steam then pushes a turbine, making it spin. As the turbine spins, a coil of wire inside a magnetic field also rotates, creating electricity through electromagnetic induction. This is a common way to generate electricity on a large scale.
In simple words: Thermal power stations burn coal to make steam, which spins a big fan called a turbine. This spinning turbine then creates electricity.

🎯 Exam Tip: Remember the energy conversion sequence in thermal power stations: chemical energy (coal) → thermal energy (steam) → kinetic energy (turbine) → electrical energy.

Question 5. What is meant by a battery or collection of cells?
Answer: A battery is formed when two or more individual cells are joined together. These cells work together to provide a larger amount of electrical power or a higher voltage than a single cell could provide alone.
In simple words: A battery is simply a group of two or more cells linked up to give more power.

🎯 Exam Tip: Understand that a "battery" is not just one cell, but typically a combination of multiple cells connected to increase power.

VII. Long Answer Questions:

Question 1. What is a cell? Explain the types of cells.
Answer: A cell is a device that changes chemical energy into electrical energy. Cells are generally grouped into two main types:
1. Primary cells:

• They cannot be recharged once their chemical energy is used up.
• They are designed for one-time use only.
• They are usually small in size.
• Examples include cells used in clocks, watches, and toys. These cells are convenient for low-power, single-use applications.

• These cells can be recharged many times after their energy is depleted.
• Their physical size can vary based on what they are used for.
• Examples include secondary cells used in mobile phones, laptops, emergency lamps, and vehicle batteries, making them ideal for repeated use.

🎯 Exam Tip: Clearly define a cell and then outline the differences between primary and secondary cells, including reusability and common examples for each type.

Question 2. What are the safety measures to safeguard a person from electric shock?
Answer: To protect someone from an electric shock, follow these important safety steps:
1. First, quickly turn off the main power supply from the switchboard. This is the most crucial step to stop the flow of electricity.
2. If you cannot turn off the main switch, carefully remove the connection from the switch controlling the electrical device.
3. Use a non-conducting material, such as a dry wooden stick or plastic object, to push the person away from the electrical source. Never touch the person directly with your bare hands.
4. After safely separating the person from the electricity, give them immediate first aid if needed and then take them to the closest health center for professional medical care.
In simple words: If someone gets an electric shock, first turn off the power. Then, use something like wood or plastic to push them away. Give them first aid and get them to a doctor quickly.

🎯 Exam Tip: Memorize the sequence of actions for electric shock first aid, emphasizing turning off power and using non-conducting materials.