Important Questions on Electric Currents for Class 7th

1. What is an electric current?
An electric current is the flow of electric charge through a conductor. It is the movement of electrons from one atom to another in a specific direction. The unit of electric current is Ampere (A).

2. What are conductors and insulators?
- Conductors: Conductors are materials that allow the flow of electric current through them easily. Examples include metals like copper, aluminum, and silver.
- Insulators: Insulators are materials that do not allow the flow of electric current through them easily. Examples include rubber, plastic, and wood.

3. How is an electric current produced?
An electric current is produced when there is a potential difference (voltage) between two points in a circuit. The electrons flow from the negative terminal of the power source towards the positive terminal, completing the circuit.

4. What is the difference between direct current (DC) and alternating current (AC)?
- Direct Current (DC): In DC, the flow of electrons is in one direction only. It is commonly used in batteries and electronic devices.
- Alternating Current (AC): In AC, the flow of electrons periodically changes direction. It is used in our homes, offices, and industries as it can be easily transmitted over long distances.

5. What is the role of a switch in an electric circuit?
A switch is a device used to control the flow of current in a circuit. When the switch is closed, the circuit is complete, and the current flows. When the switch is open, the circuit is broken, and the current stops flowing.

6. What is the difference between a series circuit and a parallel circuit?
- Series Circuit: In a series circuit, the components are connected in a single path. The same current flows through each component. If one component fails, the entire circuit will be broken.
- Parallel Circuit: In a parallel circuit, the components are connected in multiple paths. The current divides among the components. If one component fails, the current can still flow through the other components.

7. How is the brightness of a bulb affected by the number of bulbs connected in a series or parallel circuit?
- Series Circuit: In a series circuit, the brightness of the bulbs decreases as more bulbs are added because the total resistance increases, causing a decrease in current flow.
- Parallel Circuit: In a parallel circuit, the brightness of the bulbs remains the same regardless of the number of bulbs connected because each bulb receives the full voltage.

8. What is a fuse and why is it used?
A fuse is a safety device used to protect electrical circuits from excessive current. It contains a thin wire that melts and breaks the circuit when the current exceeds a certain value. This prevents damage to the circuit and reduces the risk of fire.

9. What are the precautions to be taken while handling electrical appliances?
- Do not touch electrical appliances with wet hands.
- Do not pull the plug out by its cord.
- Do not use damaged or frayed cords.
- Keep electrical appliances away from water.
- Do not overload electrical outlets.
- Unplug appliances when not in use.

10. What is the role of an electrician?
An electrician is a skilled