RBSE Solutions Class 6 Science Chapter 14 Electric Circuits

Question 1. Make a list of the places where we use an electric cell.
Answer: Electric cells are commonly used in many everyday appliances. Some places where we use them include:
1. Radio
2. Electric torch
3. Calculator
4. Remote controls of TV
5. Watches
6. Mobile phone
7. Automatic toys for kids.
Electric cells are a very portable source of power for many small electronic devices.
In simple words: We use electric cells in many small machines like radios, torches, calculators, TV remotes, watches, mobile phones, and children's toys to make them work.

🎯 Exam Tip: When listing examples, try to include a variety of items to show a broad understanding of the topic.

Question 2. Differentiate the bulb used in homes with the bulb used in torch. What are the similarities between the two.
Answer: The question asks for both differences and similarities, but the provided answer focuses on similarities. Both types of bulbs, home bulbs and torch bulbs, share several key features. They both have a glass bulb, a filament (a thin wire inside that glows), and positive and negative terminals for connection. Importantly, both types of bulbs work by converting electrical energy into light and heat.
In simple words: Both home bulbs and torch bulbs are similar because they both have a glass part, a glowing wire inside (filament), and connect to electricity using two points. They both produce light when power is supplied.

🎯 Exam Tip: When asked to differentiate and find similarities, always make sure to address both parts of the question. Pay close attention to how the light is produced.

Question 3. Sometimes we see that even in a complete electric circuit the bulb does not glow. What is the cause of it?
Answer: Even in what seems like a complete electric circuit, a bulb might not glow if the connection is not fully made, or if the wires are not properly connected. Another common reason is that the bulb itself might be damaged. For the bulb to glow, electricity must flow in a continuous, unbroken path.
In simple words: If a light bulb does not glow, it could be because the wires are not connected well, the circuit is broken somewhere, or the light bulb is faulty itself.

🎯 Exam Tip: Always check the connections, the bulb's condition, and the power source when a circuit fails to work.

Question 4. Differentiate between working bulb and fused bulb.
Answer: A working bulb has an unbroken filament made of a proper wire, allowing electricity to flow through it and make it glow. In contrast, a fused bulb has a damaged or broken filament, which stops the flow of electricity. When the filament is broken, the circuit becomes incomplete, and the bulb cannot light up.
In simple words: A working bulb has a good, whole wire inside that lights up. A fused bulb has a broken wire inside, so electricity cannot pass through it and it stays dark.

🎯 Exam Tip: The filament's continuity is the key difference; explain how it affects the circuit and light production.

Question 5. How a switch works?
Answer: A switch works by controlling the flow of electricity in a circuit. It allows electricity to flow through conductors to complete a circuit when turned "on," enabling appliances to work. When turned "off," it breaks the circuit, preventing electricity from flowing, effectively stopping the appliance. This control relies on the principle that electricity flows through conductors but not insulators.
In simple words: A switch turns things on or off by either connecting the path for electricity to flow (making it "on") or breaking that path (making it "off").

🎯 Exam Tip: Focus on how a switch creates or breaks a continuous path for electric current to flow.

Activities

Activity - 2

A simple electric circuit demonstration typically involves a cell, wires, and a bulb. When wires are properly connected, the bulb glows. When connections are incorrect or incomplete, the bulb does not glow.

Question 1. Why does this happen? Discuss.
Answer: The bulb does not glow in figure (b) because the terminals are connected incorrectly, or there is a break in the circuit. For the bulb to glow, the red wire should be connected to the positive terminal of the cell, and the black wire to the negative terminal. A complete and proper connection ensures a continuous path for electricity. If any part of the connection is faulty, the circuit becomes open, and no current flows through the bulb.
In simple words: The bulb doesn't light up if the wires are connected wrong or if there's a gap in the path electricity needs to take. Electricity needs a full loop to make the bulb glow.

🎯 Exam Tip: Always remember that a complete (closed) circuit with correct terminal connections is necessary for an electric bulb to glow.

Exercises

Choose the correct answer from the following

Question 2. Through which of the following, electricity does not flow
(a) copper
(b) iron
(c) wood
(d) aluminium
Answer: (c) wood
In simple words: Electricity can pass through metals like copper, iron, and aluminium, but it cannot pass through wood. Wood is an insulator.

🎯 Exam Tip: Remember to categorize materials into conductors (like metals) and insulators (like wood, plastic, rubber) based on how they interact with electricity.

Question 3. Which of the following is used to make electric wires?
(a) wood
(b) copper
(c) plastic
(d) thread
Answer: (b) copper
In simple words: Copper is a good material for making electric wires because electricity can easily flow through it. Wood, plastic, and thread do not let electricity pass through easily.

🎯 Exam Tip: Good conductors like copper and aluminum are preferred for electric wires due to their low resistance to current flow.

Question 4. Which of the following does not run on electricity ?
(a) fan
(b) cooler
(c) television
(d) bicycle
Answer: (d) bicycle
In simple words: Fans, coolers, and televisions need electricity to work. A bicycle runs on human power and does not use electricity.

🎯 Exam Tip: Differentiate between objects that require an electric power source and those that operate mechanically or through other means.

Fill in the blanks

Question 3. In torch the positive terminal is at
(a) bottom of the cell
(b) in upper part of brass cap
(c) in plastic cover
(d) anywhere
Answer: (b) in upper part of brass cap
In simple words: In a torch cell, the positive part is usually the metal cap at the top. The bottom is usually the negative part.

🎯 Exam Tip: Recognize the standard positive (cap) and negative (flat base) terminals of a typical dry cell or battery.

Question 4. The conducting substance is
(a) iron nail
(b) plastic refill
(c) wood
(d) all of these
Answer: (a) iron nail
In simple words: An iron nail is a metal, so it lets electricity pass through easily. Plastic and wood do not let electricity pass, making them insulators.

🎯 Exam Tip: Metals are generally good conductors of electricity, while non-metals and materials like plastic and wood are insulators.

Question 1. ........... is very important for our daily life
Answer: Electricity is very important for our daily life.
In simple words: Electricity is key to our daily lives because it powers so many things we use every day.

🎯 Exam Tip: Think about all the common devices and services that rely on electricity to function.

Question 2. The thin wire inside the bulb is called the ......
Answer: The thin wire inside the bulb is called the filament.
In simple words: The tiny wire inside a light bulb that gets hot and glows is called the filament.

🎯 Exam Tip: Understand that the filament is crucial for producing light in incandescent bulbs; its breakage causes a bulb to "fuse."

Question 3. Cell has ...... terminals.
Answer: Cell has two terminals.
In simple words: Every electric cell has two connection points: one positive and one negative.

🎯 Exam Tip: Remember that a power source always needs two distinct terminals (positive and negative) to create a circuit.

Question 4. When electric current is produced from, the filament of the bulb the light is ......
Answer: When electric current is produced from the filament of the bulb, the light is emitted.
In simple words: When electricity flows through the tiny wire (filament) inside a bulb, it gets hot and produces light, which we call emitting light.

🎯 Exam Tip: Understand the process of incandescence, where the filament glows and emits light due to heating from electric current.

Question 2. What is power house?
Answer: A power house is essentially an electricity distribution center. It is the place from where electricity is generated and then sent out to different homes and businesses. These centers ensure a continuous supply of electric power to consumers.
In simple words: A power house is where electricity is made and then sent out to homes and other places.

🎯 Exam Tip: Power houses are crucial for large-scale electricity generation and distribution to meet energy demands.

Question 3. When there is not electricity, then name two appliances used by us.
Answer: When there is no electricity, two common appliances we can use are a torch and an inverter. A torch runs on batteries, providing portable light, while an inverter provides backup electricity by converting stored energy from a battery.
In simple words: When there is no electricity, we can use a torch for light and an inverter to power some appliances from a battery.

🎯 Exam Tip: Consider non-electric or battery-powered alternatives when thinking about appliances used during power outages.

Question 4. Does generator produce electricity?
Answer: Yes, a generator does produce electricity. Generators work by converting mechanical energy (often from burning fuel or flowing water) into electrical energy. This is a fundamental principle of electricity generation.
In simple words: Yes, a generator creates electricity by turning other types of energy, like fuel, into electric power.

🎯 Exam Tip: Understand that generators convert mechanical energy into electrical energy using electromagnetic induction.

Question 5. Why we use switch in each appliance in home?
Answer: We use a switch in each appliance at home to easily turn them on and off. A switch provides a simple and safe way to control the flow of electricity to an appliance, allowing us to operate it as needed and save energy when it's not in use.
In simple words: We use switches on appliances to easily start or stop them by controlling the electricity.

🎯 Exam Tip: Switches are essential safety and convenience devices for controlling electric current in circuits.

Short Answer Type Questions

Question 1. Why the person (electrician) wears rubber gloves while climbing on an electric pole?
Answer: An electrician wears rubber gloves when working on an electric pole because rubber is a very good insulator. This means electricity cannot easily pass through it. By wearing rubber gloves, the electrician creates a barrier that prevents electricity from flowing through their body, thus protecting them from electric shocks. Safety is always a top priority when dealing with high voltage.
In simple words: Electricians wear rubber gloves because rubber stops electricity from passing through it. This keeps them safe from getting an electric shock while working.

🎯 Exam Tip: Emphasize the insulating property of rubber and its role in protecting from electrical hazards.

Question 2. Why are the handles of players and screwdrivers are covered with plastic and rubber?
Answer: The handles of tools like pliers and screwdrivers are covered with plastic and rubber because these materials are bad conductors of electricity, also known as insulators. They do not allow electric current to flow through them. This covering protects the person using the tools from getting an electric shock, especially when working on electrical wires or components. The insulating handles make the tools safe to use.
In simple words: Tool handles are covered in plastic or rubber because these materials stop electricity. This protects people from getting shocked when they use the tools.

🎯 Exam Tip: Highlight the importance of insulating materials in tool design for electrical safety.

Question 3. What is an open electric circuit? Explain by a diagram.
Answer: An open electric circuit is one where the path for electricity is broken or incomplete. In this condition, electric current cannot flow through the circuit, and any connected devices, like a bulb, will not work. It is like an unfinished road where vehicles cannot pass through.

In simple words: An open circuit is a broken path for electricity, so no electric current can flow. This means connected devices, like a bulb, will not work.

🎯 Exam Tip: Always illustrate an open circuit with a clear break or an open switch to show the interruption in current flow.

Question 4. State the differences between an open circuit and a closed circuit.
Answer: In a closed circuit, the switch is in the 'ON' position, allowing a continuous path for electric current to flow throughout the circuit. This makes any connected devices, like a bulb, operate. Conversely, in an open circuit, the switch is in the 'OFF' position or there is a break elsewhere in the circuit, interrupting the continuous path. Consequently, electric current cannot flow in an open circuit, and connected devices remain inactive. The main difference lies in the continuity of the current's path.
In simple words: In a closed circuit, electricity flows because the path is complete. In an open circuit, the path is broken, so electricity cannot flow.

🎯 Exam Tip: Focus on the "continuity of path" as the primary difference; a closed path allows current, an open path prevents it.

Long Answer Type Questions

Question 1. What is flow of electric current? Explain with a diagram.
Answer: The flow of electric current refers to the movement or transfer of electric charges through a conducting wire. When these charges move in a specific direction, it creates an electric current. For instance, when a bulb, a switch, and a battery are correctly connected in a circuit, the electric charges move from the battery through the wires and the bulb. This movement causes the bulb to glow, showing the presence of electric current. This continuous flow is essential for electrical devices to function.

In simple words: Electric current is when tiny electric charges move through a wire. When they move in a full circle with a battery and switch, it makes things like a light bulb turn on.

🎯 Exam Tip: Always describe electric current as the flow of charges and illustrate it with a simple closed circuit diagram showing all components.

Question 2. Take a used cell and break it to open apart. Now examine and describe each and every contact of the cell in detail.
Answer: A typical dry cell has several parts. It consists of a graphite rod placed at the center, which acts as the positive terminal. This rod is surrounded by a moist paste, often made of ammonium chloride and manganese dioxide. All of this is contained within a metal cylinder, usually made of zinc, which serves as the negative terminal. These internal components are carefully arranged to enable the chemical reactions that produce electricity. The external metallic cap at the top is connected to the graphite rod (positive), and the bottom flat surface is the zinc case (negative).

In simple words: A dry cell has a zinc metal outer case which is negative, and a carbon rod in the middle which is positive. Inside, there's a wet paste that helps make electricity.

🎯 Exam Tip: Remember the key components: zinc casing (negative), carbon rod (positive), and the chemical paste inside.

Question 3. Describe the structure of an electric bulb used in torches. Also draw its well labelled diagram.
Answer: A torch bulb is a small electric light source. It consists of a spherical glass cover that protects the internal components. Inside this glass bulb, there is a thin wire called a filament, usually made of tungsten. This filament is supported by two thicker wires. One of these thicker wires connects to the metallic base of the bulb, which serves as one of the electrical terminals (often negative). The other thick wire connects to the metal tip at the very bottom of the bulb, acting as the other electrical terminal (often positive). When electricity flows through the filament, it heats up and produces light. The metallic base helps in fitting the bulb securely and making electrical contact.

In simple words: A torch bulb has a glass outer part with a tiny glowing wire (filament) inside. This wire is connected by thicker wires to a metal base and a metal tip, which are used to connect it to a battery.

🎯 Exam Tip: When drawing, clearly label the filament, thick wires, glass bulb, metallic base, and tip to show the bulb's structure.

Practical Work

Question 1. Find out about the life of the invertor of electric bulb – Thomas Alva Edison, and write it your note – book.
Answer: Thomas Alva Edison, a famous American inventor, was born in Milan, Ohio, and grew up in Port Huron, Michigan. He started his career with inventions like the automatic repeater and improved telegraphic devices. However, he first gained wide recognition for inventing the phonograph. Edison was a very productive inventor, making many other famous inventions such as the vote recorder, printing telegraph, and carbon telephone transmitter. He conducted over 1000 experiments before successfully inventing the electric bulb. Thomas Edison passed away on October 18, 1931. His inventions greatly changed the world.
In simple words: Thomas Alva Edison was a great inventor from America who invented many things, including the phonograph and, famously, the electric light bulb after many tries. He died in 1931.

🎯 Exam Tip: When writing about inventors, include key milestones, famous inventions, and the impact of their work.

Activity: Simple Electric Circuit with Cell Holder

A cell holder is used to keep cells securely in place and ensure proper electrical connection in a circuit. The metallic wire of the holder connects to the negative terminal of the cell, while the positive end of the holder touches the positive terminal of the cell at the top. The bulb then fits into the holder, completing the circuit.

Question 3. Alessandro volta is the scientist who made the first cell, that cell is called the voltaic cell, after his name. Take a pot of glass, fill it with water and add common salt in it to make a common salt solution. Now insert a copper and a zinc rod (electrodes) into it (make sure that they do not touch each other.) Now connect a 1.5 volt electric bulb or a LED through the two rods and pass the current. Does the bulb or LED light up? Now repeat the same activity by taking a plastic container and filling that with cow dung or mud from the field and inserting the same rods again.
Answer: Yes, the bulb starts to glow when connected to the copper and zinc rods in both the salt water solution and the cow dung/mud mixture. This experiment demonstrates how a simple voltaic cell works, producing electricity from chemical reactions. Students should perform this activity themselves to observe this effect directly, which helps understand how basic batteries are made.
In simple words: Yes, the light bulb will glow. This experiment shows how simple things like salt water or even mud can create electricity when different metals are placed in them.

🎯 Exam Tip: Focus on identifying the components (electrodes, electrolyte) and the outcome (bulb glowing) of this simple battery experiment.

Other Important Questions

Multiple Choice Questions

Question 1. The appliance which is not operated by electricity
(a) bridge
(b) electric bulb
(c) hand fan
(d) T.V.
Answer: (c) hand fan
In simple words: An electric bulb, fan, and TV all need electricity to run. A hand fan, which you wave with your hand, does not use electricity.

🎯 Exam Tip: Carefully distinguish between items that require an electrical power source and those that operate manually.

Short Answer Type Questions

Question 1. Draw labelled diagram of a cell.
Answer:

In simple words: This diagram shows a basic electric cell, with its top metal cap as the positive (+) terminal and the flat bottom as the negative (-) terminal.

🎯 Exam Tip: Ensure your diagram clearly shows the positive and negative terminals, as these are the crucial parts for connecting a cell in a circuit.

Question 2. Make a list of appliances based on electricity in your home.
Answer: Many appliances in our homes use electricity to function. Here is a list of common electric appliances:
1. Television
2. Fridge
3. Radio
4. Electric press (iron)
5. Microwave
6. Washing machine
7. Compact disc player
8. Electric bulb
9. Tube light
10. Vacuum Cleaner
These devices make our daily lives easier and more comfortable.
In simple words: We have many electric machines at home like TV, fridge, radio, iron, microwave, washing machine, CD player, light bulbs, tube lights, and vacuum cleaners.

🎯 Exam Tip: When listing appliances, try to categorize them mentally (e.g., for entertainment, cooking, cleaning) to ensure you cover a good range.

Long Answer Type Questions

Question 1. What are conductors and insulators of electricity? Give examples.
Answer:
Electric Conductor: These are substances through which electricity can flow very easily. They have free electrons that allow electric current to pass through them without much resistance. A good example is metals. This property makes them useful in wires and electrical components.
Example: Iron, silver, copper, common salt solution (NaCl solution), graphite, and electrolyte solutions.
Non-Conductor of Electric (Insulator): These are substances through which electricity cannot flow easily, or at all. Insulators do not have free electrons, so they resist the passage of electric current. They are used to prevent electric shocks and to contain electricity within circuits.
Example: Dry wood, non-metals like mica, pure water, glass, plastic, and rubber.
In simple words: Conductors are materials like metals that let electricity pass through them easily. Insulators are materials like plastic or wood that do not let electricity pass through, keeping us safe.

🎯 Exam Tip: Clearly define both terms and provide distinct examples for each, focusing on the ability or inability to conduct electricity.