EASY
7th West Bengal Board
IMPORTANT
Earn 100

Question Image
Hold the bar magnet as shown in the figure. Touch a nail to one of its poles and allow it to cling to the magnet. Touch another nail to the first one and leave it. What can you see? Why is the second nail hanging from the first one? Why is it not falling?

Important Questions on Physical Environment

MEDIUM
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 26
Question Image
In the above picture, is the first nail attracting the second nail? Why?
MEDIUM
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 26
Question Image
Take several nails and see whether you can make a chain of hanging nails. Now carefully hold the first nail (in direct contact with the magnet) take care so that no nail falls from the chain. Slowly take away the magnet. What can you see? Why do the nails fall?
EASY
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 27
Could you separate the two poles of the magnet?
EASY
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 28
A suspended bar magnet points north-south. If a friend of yours approaches it with another magnet in his pocket, what will happen? Will the suspended magnet still point towards north-south?
EASY
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 28
Do you know under which influence does the suspended magnet change its direction?
EASY
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 28
Why does a suspended magnet point towards the North-South direction even when there is no other magnet near it?
EASY
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 28
Is there any other magnet near it that influences the suspended magnet? Earth itself is that magnet?
MEDIUM
7th West Bengal Board
IMPORTANT
Environment and Science Class 7>Chapter 1 - Physical Environment>Exercise 29

Question Image

Take an iron bar, a long insulated electrical wire, a switch, a powerful battery, and a magnetic needle. Coil the wire around the iron bar as shown in the figure. Connect the two ends of the wire to the two ends of the battery through a switch (as shown in the picture). Now bring a magnetic needle near the iron bar and switch on the circuit. Try to understand what kind of pole has been created at the end of the iron bar nearer to the needle. Now interchange the two ends of the wire that are attached to the battery. Repeat the experiment once again, and observe which end of the needle is attracted (or repelled) by which end of the iron bar. Why does the needle deflect? Which external body applies a force upon the poles of the needle?