1. Pick the change that can be reversed from the following. *
1 point
Cutting of trees
Melting of ghee
Burning of candle
Blooming of flower
2. Which of the following changes cannot be reversed? *
1 point
Hardening of cement
Freezing of ice cream
Opening of door
Melting of chocolate
3. While lighting a candle. Paheli observed the following changes. (a) Wax was melting. (b) Candle was burning. (c) Size of the candle was reducing. (d) Melted wax was getting solidified. Of the above, the changes that can be reversed are: *
1 point
(a) and (b)
(b) and (c)
(c) and (d)
(a) and (d)
4. An iron ring is heated. Which of the following statement about it is INCORRECT? *
1 point
The ring expands.
The ring almost comes to the same size on cooling.
The change in this case is reversed.
The ring changes its shape and the change cannot be reversed.
5. Rolling of chapatti and baking of chapatti are the changes that *
1 point
can be reversed.
cannot be reversed.
can be reversed and cannot be reversed, respectively.
cannot be reversed and can be reversed, respectively.
6. Iron rim is made slightly smaller than the wooden wheel. The rim is usually heated before fixing into the wooden wheel because on heating the iron rim *
1 point
expands and fits onto the wooden wheel.
contracts and fits onto the wooden wheel.
no change in the size takes place.
expands first, then on cooling contracts and fits onto the wooden wheel.
7. When ice melts to form water, then a change occurs in its: *
1 point
position
temperature
state
composition
8. Which of the following is a beneficial change? *
1 point
Rusting of iron objects.
Spoilage of food
Ripening of fruit
Souring of milk
9. When ice cream melts, *
1 point
Heat is lost from the ice cream and heat is gained by the air.
Heat is gained by the ice cream and heat is lost from the air.
10. An irreversible change takes place when: *
1 point
Salt is added to water.
Charcoal burns.
Ice melts.
An iron nail is magnetised.
Answers
Explanation:
1 point
Cutting of trees
Melting of ghee
Burning of candle
Blooming of flower
2. Which of the following changes cannot be reversed? *
1 point
Hardening of cement
Freezing of ice cream
Opening of door
Melting of chocolate
3. While lighting a candle. Paheli observed the following changes. (a) Wax was melting. (b) Candle was burning. (c) Size of the candle was reducing. (d) Melted wax was getting solidified. Of the above, the changes that can be reversed are: *
1 point
(a) and (b)
(b) and (c)
(c) and (d)
(a) and (d)
4. An iron ring is heated. Which of the following statement about it is INCORRECT? *
1 point
The ring expands.
The ring almost comes to the same size on cooling.
The change in this case is reversed.
The ring changes its shape and the change cannot be reversed.
5. Rolling of chapatti and baking of chapatti are the changes that *
1 point
can be reversed.
cannot be reversed.
can be reversed and cannot be reversed, respectively.
cannot be reversed and can be reversed, respectively.
6. Iron rim is made slightly smaller than the wooden wheel. The rim is usually heated before fixing into the wooden wheel because on heating the iron rim *
1 point
expands and fits onto the wooden wheel.
contracts and fits onto the wooden wheel.
no change in the size takes place.
expands first, then on cooling contracts and fits onto the wooden wheel.
7. When ice melts to form water, then a change occurs in its: *
1 point
position
temperature
state
composition
8. Which of the following is a beneficial change? *
1 point
Rusting of iron objects.
Spoilage of food
Ripening of fruit
Souring of milk
9. When ice cream melts, *
1 point
Heat is lost from the ice cream and heat is gained by the air.
Heat is gained by the ice cream and heat is lost from the air.
10. An irreversible change takes place when: *
1 point
Salt is added to water.
Charcoal burns.
Ice melts.
An iron nail is magnetised.