Electricity and Circuits — Class 6 Science Notes & Questions
This post covers the NCERT Class 6 chapter Electricity and Circuits. The Notes section explains key concepts in simple language and gives practical tips and examples. The Questions & Answers section includes 7 MCQs (with choices), 7 very short, 7 short and 7 long answer questions — perfect for exam practice and revision.
Notes — Electricity and Circuits (Simple & Exam Friendly)
Electricity is a form of energy that powers many devices around us. In Class 6 science, we begin by understanding basic ideas like electric charge, conductors and insulators, simple circuits, and safety rules. Learning these basics helps you to draw circuit diagrams, perform simple class experiments, and answer exam questions confidently.
What is Electric Charge?
Matter is made of atoms. Some particles in an atom carry tiny charges. When there is an imbalance of these charges on an object, we say the object is electrically charged. Charging by rubbing (like rubbing a plastic ruler with wool) causes one object to gain electrons and become negatively charged and the other to lose electrons and become positively charged. This is called static electricity.
Static Electricity vs Current Electricity
Static electricity stays on the surface of objects and does not flow. Current electricity flows through a path and powers devices. In this chapter, our main focus is on current electricity — how electric current flows through materials and how we make simple circuits.
Conductors and Insulators
Materials that allow electric current to pass through them are called conductors (for example, copper, aluminium). Materials that do not allow current to pass easily are called insulators (for example, rubber, plastic, wood). Wires used in circuits are usually copper covered with a plastic insulator to prevent shocks.
What is an Electric Cell and a Battery?
A cell is a device that produces electricity through chemical reactions. A common example is an AA battery (a cell). When two or more cells are joined, they form a battery which gives a stronger or longer-lasting source of electricity.
Simple Electric Circuit — Components
A simple circuit usually has these parts:
- Electric cell or battery (source of electricity)
- Connecting wires
- A bulb (or any electrical device)
- A switch (to open/close the circuit)
When the switch is closed (ON), the circuit is complete and current flows so the bulb lights. When the switch is open (OFF), the circuit is broken and current stops.
Open Circuit vs Closed Circuit
A closed circuit means there is a complete path for current to flow. An open circuit means the path is broken (for example the switch is OFF or a wire is disconnected) so current cannot flow.
Drawing Circuit Diagrams and Symbols
To communicate circuits easily, we use standard symbols: a short and long line for a cell, a circle with a cross for a bulb, straight lines for wires, and an angled line for a switch. Practice drawing simple circuit diagrams for class tests.
How to Make a Simple Circuit (Class Activity)
Steps: Connect one end of a wire to the positive terminal of the cell and the other end to the bulb’s metal base. Attach another wire from the bulb’s other metal contact to the negative terminal of the cell. Close the circuit; the bulb should light. If using a switch, insert it into one wire to open/close the circuit.
Series and Parallel (Introductory)
In a series circuit, components are connected one after another along a single path. If one goes off, the whole circuit stops. In a parallel circuit, components are connected on multiple paths; if one bulb goes, others still glow. At Class 6 level, understand the idea and typical classroom examples (string of old holiday lights vs home bulbs).
Safety Rules
- Never touch electric appliances with wet hands.
- Do not pull a plug by the wire — hold the plug.
- Report broken wires or sparks to an adult and do not use the appliance.
- Use fuses and switches to prevent short circuits and overloads.
Practical Uses & Everyday Examples
Electricity runs lights, fans, refrigerators, televisions, and chargers. Understanding circuits helps you fix small classroom experiments and improves logical thinking about how devices are connected.
Questions & Answers — Practice Section
7 MCQs (choose the correct option)
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Q1. Which of the following is a conductor?
A. Rubber B. Glass C. Copper D. Wood
Ans: C. Copper -
Q2. A complete path for electricity to flow is called a:
A. Open circuit B. Closed circuit C. Short circuit D. Broken circuit
Ans: B. Closed circuit -
Q3. The device used to switch on and off an electric circuit is called:
A. Bulb B. Resistor C. Switch D. Cell
Ans: C. Switch -
Q4. Insulators are used to:
A. Allow current easily B. Prevent flow of current C. Make more current D. Store electricity
Ans: B. Prevent flow of current -
Q5. Which symbol represents a cell in a circuit diagram?
A. Circle with cross B. Short and long lines C. Zig-zag line D. Square box
Ans: B. Short and long lines -
Q6. If one bulb in a series circuit stops glowing, the others will:
A. Continue to glow B. Glow more brightly C. Stop glowing D. Change color
Ans: C. Stop glowing -
Q7. Which material is commonly used for electric wires?
A. Plastic only B. Iron C. Copper coated with plastic D. Glass coated with rubber
Ans: C. Copper coated with plastic
7 Very Short Answer Questions
- Q: What is meant by a switch?
A: A switch is a device used to open or close an electric circuit to stop or permit current flow. - Q: Define a bulb in a circuit.
A: A bulb is a device that converts electrical energy into light (and some heat) when current passes through it. - Q: Name one source of electricity used in simple circuits.
A: Electric cell (battery). - Q: What does an insulator do?
A: It prevents the flow of electric current through it. - Q: Give one example of static electricity.
A: Rubbing a balloon on hair and it sticking to a wall. - Q: What happens in an open circuit?
A: The path is broken and current does not flow. - Q: Why do wires have plastic coating?
A: To insulate them and prevent electric shocks.
7 Short Answer Questions
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Q: Explain why copper is used in wires.
A: Copper is a good conductor of electricity — it allows current to pass easily. It is also flexible, does not corrode quickly, and is affordable, making it ideal for making wires. -
Q: Describe a simple experiment to show current flow.
A: Connect a cell, bulb, and wires as shown in class (cell → wire → bulb → wire → cell). When the circuit is complete, the bulb lights, showing current flow. Break the circuit and the bulb goes off. -
Q: What is a circuit diagram?
A: A circuit diagram uses standard symbols to represent components of an electric circuit on paper so that the circuit can be understood and reproduced easily. -
Q: Give two differences between open and closed circuits.
A: In a closed circuit current flows and devices work; in an open circuit current cannot flow and devices stop working. A closed circuit has no break; an open circuit has a break (like an open switch). -
Q: How can we prevent electric hazards at home?
A: Use proper insulation on wires, avoid overloading sockets, keep appliances away from water, and always switch off appliances when not in use. -
Q: Why is the plastic covering not a conductor?
A: Plastic has very few free electrons and resists the movement of charge; thus it acts as an insulator preventing current flow. -
Q: What is meant by the term 'short circuit' in simple words?
A: A short circuit occurs when current takes an unintended low-resistance path, often causing excessive current and heat. This can damage wires or cause fires if not protected by fuses.
7 Long Answer Questions
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Q: Explain how a cell produces electric current and how to connect cells to get more power.
A: A cell produces electric current through chemical reactions between its internal chemicals and electrodes. When connected to an external circuit, these reactions push charges through the wire creating a current. To get more power or voltage, cells can be connected in series (end to end), which adds the voltages of individual cells. In school circuits, two or more cells joined in series form a battery. However, always use the number of cells recommended for bulbs to avoid burning them. -
Q: Describe the components of a simple circuit and how each part works.
A: The main components are the cell (source of energy), wires (pathway for electrons), bulb (device that glows when current passes), and switch (controls the flow). The cell pushes electrons, wires provide a path, the bulb’s filament resists electron flow and glows, and the switch opens or closes the path to control the flow. -
Q: Discuss series and parallel connections and state one advantage of each.
A: In a series connection components are in a single path; the advantage is simplicity and fewer wires. In parallel connections components have separate paths to the source; the advantage is that each component works independently — if one fails, others still operate. -
Q: Why do we use fuses or circuit breakers in homes? Explain with safety examples.
A: Fuses and circuit breakers prevent damage from excessive current (overload or short circuit). They cut off the current when it goes too high, protecting wires and preventing fires. For example, if too many appliances run on one socket, the fuse blows and stops current flow, avoiding overheating. -
Q: How can we make a bulb glow brighter? Give two ways with explanation.
A: Use a cell with higher voltage (more cells in series) or reduce resistance in the circuit (use thicker wires and fewer resistive components). More voltage pushes more current through the bulb, making it glow brighter. -
Q: Explain why we must not repair an electric appliance without switching off its power supply.
A: Live wires can cause electric shocks. Even a small contact with a live conductor can let current pass through the body into the ground, causing injury or worse. Always switch off and unplug the appliance before opening or repairing it. -
Q: Describe a classroom project to show the difference between a series and parallel circuit.
A: Prepare two boards. On board A connect two bulbs in series with a cell and switch; on board B connect two bulbs in parallel with the same cell. Close both switches. Note brightness: in series bulbs are dimmer; in parallel each bulb glows brightly even if the other is removed. Ask students to remove a bulb in each circuit to see the effect, demonstrating independence in parallel vs dependence in series.
Keep this post handy while revising — practice the circuit diagrams and the class experiment at least twice to remember the steps and safety rules.
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