Science 2 Marks Questions

Use a Circuit: Connect the battery to a light bulb. The correct connection will make the bulb glow brightly.
Check the Shape: The flat side is usually the negative (-) terminal, and the smaller protruding side is positive (+) terminal.

Reasons :
(a) Loose Connections: Ensure sill wires are securely connected to the batteiy, lamp, and switch.
(b) Burnt-out Bulb: Tiy replacing the bulb with a new one to see if it works.
(c) Dead Battery: Check if the battery is providing power by testing with a multimeter.
(d) Faulty Switch: Test the switch by bypassing it (connect the wires directly) to see if the lamp glows.

In Fig., the lamps are connected end to end (as indicated by the circuit diagram). If the filament of one of the lamps is broken, the other lamp will not glow. This is because in a line circuit, the current flows through all components one after another. If one component (like a lamp) is broken, the entire circuit is interrupted, and the current cannot flow through the rest of the circuit.

The LED bulb will glow when the longer wire i.e., the positive terminal of LED is connected with positive terminal of battery and shorter wire i.e., the negative terminal of LED is connected with negative terminal of battery.
According to the given connection the LED will not glow, as negative terminal of LED is connected with positive terminal of battery. The correct connection will be :

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When the switch is in the ‘OFF’ position, the circuit from the positive terminal of the battery to the negative terminal is incomplete. The circuit is then said to be open, and no current flows through the circuit, causing the

We should never touch a lighted electric bulb connected to the mains because it may be very hot, and touching it could result in serious burns. Similarly, we should avoid experimenting with electrical supplies from the mains, a generator, or an inverter, as they may cause an electric shock.

When the switch is in the ‘ON’ position, the circuit from the positive terminal of the battery to the negative terminal is complete. The circuit is then said to be closed and current flows through the circuit, causing the bulb to glow.

A battery is a combination of two or more cells. It is constructed by placing the cells properly in a cell holder so that the positive terminal of one cell is connected to the negative terminal of the next cell. A metal wire is then connected to each of the two metal

Observation and conclusion: The electric lamp will glow only when the current will flow inside the circuit. When all the connections are properly connected then only current will flow and the lamp will glow otherwise the current will not flow in the circuit and the lamp will not glow.

Observation and conclusion: The LED glows only when it is connected correctly the longer wire to the positive terminal and the shorter wire to the negative terminal of the battery as shown in fig.(a). This shows that electric current flows in only one direction through an LED. If the connections are reversed, the LED does not glow. This helps us learn how to properly connect components in a circuit.

Observation and conclusion: LEDs do not have filaments like incandescent lamps. They have two terminals one positive (longer wire) and one negative (shorter wire). The LED lights up when connected correctly to a battery. Some torch lamps may use LEDs of different shapes and colours.

Observation and conclusion: The glowing part of an incandescent lamp is a thin wire called the filament. The filament gets hot and glows when electricity passes through it, producing light. It is connected to two thicker wires that act as terminals. These wires are fixed in a way that they do not touch each other inside the lamp.

Observation and conclusion: The torchlight glows only when the cells are placed in the correct order, with the positive terminal of one cell connected to the negative terminal of the next. This correct arrangement forms a battery, which allows electricity to flow and light the lamp.

Conclusion: An electric cell has two terminals a positive terminal (metal cap) and a negative terminal (metal disc). These terminals help in the flow of electric current. The electric cell acts as a portable source of electrical energy.

Observation and conclusion: The torchlight glows when the switch is turned on because the electric cells inside provide energy to the lamp. When the switch is off, the circuit breaks and the lamp does not glow. This shows that a complete circuit is needed for electricity to flow.

No, the lamp will not glow in this case. The insulator covering on the connecting wires prevents the flow of electric current. Since the current cannot pass through the insulated parts of the wires, the circuit remains incomplete, and the lamp will not light up.

Electric wires are covered with plastic or rubber because these materials are insulators. They prevent electric current from escaping the wires and also protect people from electric shocks. Additionally, the insulation keeps the wires from touching each other and causing short circuits.

Metal wires (usually copper) are used because metals are good conductors of electricity. They allow electric current to flow easily. While other materials could be used but they would not conduct electricity as efficiently. For example, rubber and plastic are insulators, so they can’t carry current.

Yes, the circuit (often representing components like cells, bulbs, or switches in a circuit diagram) can be represented by symbols. For example, a battery is represented by a pair of short and long parallel lines, and a lamp is represented by a circuit with an ‘X’ inside it.

The switch controls the flow of electricity in the circuit. When the switch is ‘ON’, it closes the circuit, allowing electricity to flow through the lamp and make it glow. When the switch is ‘OFF’, it opens the circuit, stopping the flow of electricity, and the lamp goes off.

The torch lamp glows when the switch is in the ‘ON’ position because it completes the electrical circuit, allowing current to flow through the lamp. When the switch is in the ‘OFF’position, the circuit is open, and current cannot flow, so the lamp does not glow

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It's crucial to check the terminal markings on cells because electrical devices need the current to flow in a specific direction to function properly. Cells have a positive (+) and a negative (-) terminal, and if you connect them backward, the device might not work or could even be damaged.Therefore, ensuring correct connections with proper terminal markings is essential for the device to operate as intended and to prevent any potential damage.

No, silk fiber will not work.
This is because silk is an insulator and does not allow electricity to pass through it.Circuits need conductors like metal wires to function.

The torch might not work due to incorrect cell placement, where the positive and negative ends aren't properly aligned. 

Without electricity, modern communication would be impossible. There would be no mobile phones, computers, or internet, so we would have to rely on slower methods like postal services and messengers. News and information would spread slowly with no television or radio, and emergency services would struggle to respond quickly, severely limiting global connectivity and making communication slower and less reliable.

Plastic is an insulator. If all the wires in your home were made of plastic, electricity would not be able to flow through them.Since electricity couldn't reach your lights, appliances, or other devices, nothing would work.

Using the correct symbols in circuit diagrams is essential because these diagrams serve as a universal language for electrical and electronic circuits. Just like a map uses specific symbols to represent different landmarks, circuit diagrams use standardized symbols to represent components like resistors, capacitors, voltage sources, and transistors. 

The filament is a thin wire inside an incandescent light bulb that gets very hot when electricity passes through it.This heat causes the filament to glow, producing light. So, the filament's main job is to convert electrical energy into light energy.

If we put a cell in a torch backward, the torch lamp will not glow.The electric current needs to flow in the correct direction for the circuit to work. Reversing the cell breaks this flow.