Fun with magnets Worksheet-3

Fun with magnets Worksheet-3

Multiple-Choice question:

21. What would happen if a powerful magnet is rubbed slowly again and again against an aluminum piece?

(a) A magnet will get demagnetized

(b) That piece will get magnetized

(c) No effect

22. Can we give a desired shape to natural magnets?

(a) Yes, we can create natural magnet of any shape

(b) No, hammering or striking may damage magnets

(c) Can’t say

23. Which of the following substance is attracted to a magnet?

(a) water              (b) iron                (c) lead                (d) silver

24. What characteristics do magnetic substances have?

(a) Fall faster under gravity than other non-magnetic substance

(b) Are always black and cold to touch

(c)  Can exert force on other magnetic substances at a distance (not in contact with each other)

(d) Give “shock” when we touch them

25. An electromagnet shows magnetic properties when-

(a) If electric current is switched off

(b) If electric current is switched on

(c) It is kept in contact with another magnet for long period of time

(d) It is heated and beaten

26. Which of the following material is non-magnetic?

(a) Copper           (b) Nickel             (c) Steel               (d) Iron

27. What name was given to the special rock used to help find directions?

(a) lodestone       (b) polerock        (c) magic rock     (d) wayfinder

28. Who were the first to use magnetic rock, magnetite, as a compass?

(a) British             (b) Chinese (c) Romans (d) Greeks

29. Which of the following material is attracted to a magnet i.e. magnetic?

(a) Copper           (b) Plastic            (c) Iron                 (d) Brass

30. Which of the following is true about the magnetic field?

(a) Exists only outside the magnet in all directions around it

(b) Exists only inside the magnet in all directions around it

(c) Exists inside and outside the magnet in all directions around it

(d) Exists only at the poles of magnet

Answer Key:

21. (c)
22. (b)
23. (b)
24. (c)
25. (b)
26. (a)
27. (a)
28. (b)
29. (c)
30. (c)