5. Complete Activity 10.5 (Page 116). Take the cardboard tray from inside a discarded matchbox. Wrap an electric wire a few times around the cardboard tray. Place a small compass needle inside it. Now connect the free ends of this wire to an electric cell through a switch as shown in Fig. 10.17. Note the direction in which the compass needle is pointing. Bring a bar magnet near the compass needle. Observe what happens. Now, while watching the compass needle carefully, move the switch to the ‘ON’ position. What do you observe? Does the compass needle deflect? Move the switch back to the ‘OFF’ position. Does the compass needle come back to its initial position? Repeat the experiment a few times. What does this experiment indicate?
Answer:
Activity 10.5 can be carried out as follows:
Aim: To examine if electric current can make a magnetic compass needle deflect and make the necessary conclusions based on that.
Materials Required: Matchbox, electric wire, small compass needle, electric cell, switch.
Procedure:
(i) Take out the cardboard tray from inside a discarded matchbox and wrap the electric wire a few times around the cardboard tray. Place a small compass needle inside the tray and connect the free ends of this wire to an electric cell through a switch.
(ii) Note the direction in which the compass needle is pointing and then bring a bar magnet near the compass needle. Observe if the compass needle deflects.
(iii) Now take away the magnet and switch on the current in the circuit. Observe if the compass needle deflects.
(iv) Switch off the current and observe if the compass needle comes back to its initial position.
(v) Repeat the experiment a few times and make the necessary conclusions.
Observations:
- The needle deflects when the bar magnet is brought close to it.
- The needle also deflects when the electric current is switched on in the circuit.
- The needle comes back to its original position when the current is switched off.
- The same observations hold every time the experiment is repeated.
Conclusions: We can conclude that when electric current passes through a wire, the wire behaves like a magnet. This is known as the magnetic effect of electric current.
“Take the cardboard tray from inside a discarded matchbox. Wrap an electric wire a few times around the cardboard tray. Place a small compass needle inside it. Now connect the free ends of this wire to an electric cell through a switch as shown in Fig. 10.17. Note the direction in which the compass needle is pointing. Bring a bar magnet near the compass needle. Observe what happens. Now, while watching the compass needle carefully, move the switch to the ‘ON’ position. What do you observe? Does the compass needle deflect? Move the switch back to the ‘OFF’ position. Does the compass needle come back to its initial position? Repeat the experiment a few times. What does this experiment indicate?” – Solved.
Related Links:
Solution to Extended Learning Problem 1
Solution to Extended Learning Problem 2
Solution to Extended Learning Problem 3
Solution to Extended Learning Problem 4
Solution to Activity 10.1
Solution to Activity 10.2
Solution to Activity 10.3
Solution to Activity 10.4
Solution to Activity 10.5
Solution to Activity 10.6
