SSC Worksheet for Chapter - 6 Electric Current Class 8

Worksheets For class 8

Find SSC Worksheet for chapter-6 Electric Current class 8

CLASS-8

BOARD: SSC

Physics Worksheet -6

TOPIC: Electric Current

For other SCC Worksheet for class 8 Science check out main page of Physics Wallah.

Fill in the blanks :

1. When electric current flows through a wire electrons flow from ________ terminal to ________ terminal through the wire.

2. Current in a circuit can be started and stopped by operating the ________ .

3. The ________ in home appliances plays the role played by the key in an electric circuit.

4. In the simple cell ________ acts as negative pole and ________ acts as positive pole as cell.

5. The electrolyte used in the simple cell is ________ .

6. The cell that can be recharged repeatedly is ________ cell.

7. The button cell is also called ________ cell.

8. The cell in which chemical reaction proceeds very slowly, leading to longer life of the cell is ________ cell.

9. Explain in brief the working of electric bell.

10. Write a note on electromagnets.

11. What is electromagnetic induction?

12. What is electromotive force?

13. What are the types of electrochemical cells ?

14. Draw a circuit diagram with electric cell, key, electric bulb and connecting wires.

Solutions: to worksheet-6 Topic- Electric Current

1. Negative, positive

2. Key

3. Switch

4. Zinc, Copper

5. Sulphuric acid

6. Nickel-cadmium

7. Lithium cell

8. Dry cell

9. An electric bell is made up of a coil of wire wound on an iron piece which acts as an electromagnet, when the electric current is passed through it. An iron strip with a hammer at one end is kept close to the electromagnet. There is a contact screw near the iron strip.

When the switch is in the 'ON ' position, the current flows through the coil, it becomes an electromagnet. It pulls the iron strip and the hammer at the end of the strip strikes the gong to produce sound. When the electromagnet pulls the iron strip, the circuit breaks and the current stops flowing. The above process is repeated again and again to continue producing sound.

10. An electromagnetis a type ofmagnetin which themagnetic fieldis produced by the flow of electric current. The magnetic field disappears when the current is turned off. Electromagnets are widely used as components of other electrical devices, such asmotors,generators,relays,loudspeakers,hard disks,MRI machines, scientific instruments, and magnetic separationequipment, as well as being employed as industrial lifting electromagnets for picking up and moving heavy iron objects like scrap iron.

11. Electromagnetic induction (or sometimes justinduction) is a process where a conductor placed in a changing magnetic field (or a conductor moving through a stationary magnetic field) causes the production of a electrical current- it is said toinducethe current

12. Electromotive force (emf) is a measurement of the energy that causes current to flow through a circuit. Electromotive force is also known as voltage, and it is measured in volts. Electromotive force is not truly a force; rather, it is a measurement of energy per unit charge

13. There are two basic types of electrochemical cell

(a) Voltaic Cell (=galvanic cell) which generates electricity as a result of the cell reaction, which is a spontaneous (thermodynamically favorable) process.

(b) Electrolytic Cell: a non-spontaneous cell reaction is driven to occur by the application of an external source of current.