Saturday, 8 September 2018

CBSE Class 6 - Science - Chapter 6 - Changes Around Us - Multiple Choice Questions (#cbsenotes)(#eduvictors)

Class 6 - Science - Chapter 6 
Changes Around Us
CBSE Class 6 - Science - Chapter 6 - Changes Around Us - Multiple Choice Questions (#cbsenotes)(#eduvictors)


Multiple Choice Questions


Q1: Pick the change that can be reversed from the following.

(a) Cutting of trees
(b) Melting of ghee
(c) Burning of candle
(d) Blooming of flower


Q2: Which of the following changes cannot be reversed?

(a) Hardening of cement
(b) Freezing of ice cream
(c) Opening a door
(d) Melting of chocolate


Q3: An iron ring is heated. Which of the following statement about it is incorrect?

(a) The ring expands
(b) The ring almost comes to the same size on cooling
(c) The change, in this case, is reversed
(d) The ring changes its shape and the change cannot be reversed





Q4: While lighting a candle, Paheli observed the following changes:

1. Wax was melting.
2. A candle was burning.
3. Size of the candle was reducing.
4. Melted wax was getting solidified.

Of the above, the changes that can be reversed are
(a) (1) and (2)
(b) (2) and (3)
(c) (3) and (4)
(d) (1) and (4)


Q5: Salt can be separated from its solution (salt dissolved in water) because

(a) mixing of salt in water is a change that can be reversed by heating and melting of salt
(b) mixing of salt in water is a change that cannot be reversed
(c) mixing of salt in water is a permanent change
(d) mixing of salt in water is a change that can be reversed by evaporation



Q6: Rolling of chapatti and baking of chapatti are the changes that

(a) can be reversed
(b) cannot be reversed
(c) can be reversed and cannot be reversed, respectively
(d) cannot be reversed and can be reversed, respectively


Q7: 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

(a) expands and fits onto the wooden wheel
(b) contracts and fits onto the wooden wheel
(c) no change in the size takes place
(d) expands first, then on cooling contracts and fits onto the wooden wheel


Q8: Which of the following change is non-periodic?

(a) heartbeat
(b) earthquake
(c) an occurrence of day and night
(d) oscillation of pendulum


Q9: Spoilage of food is ___________

(a) reversible change
(b) fast change
(c) undesirable change
(d) periodic change


Q10: Salt is separated from seawater by

(a) evaporation
(b) condensation
(c) decantation
(d) filtration


Answers:
1: (b) Melting of ghee
Melting of ghee is a reversible change because, on melting, ghee turns into liquid form and after cooling it returns back to its original form.

2: (a) Hardening of cement
Hardening of cement is an irreversible change. Changes that cannot be reversed are called irreversible changes.

3: (d) The ring changes its shape and the change cannot be reversed

4: (d) (1) and (4)
Melting of wax and solidification of melted wax, both can be seen in case of lighting a candle.

5: (d) mixing of salt in water is a change that can be reversed by evaporation
Note: The common salt dissolved in water can be separated by the process of evaporation.

6: (c) can be reversed and cannot be reversed, respectively

7: (d) expands first, then on cooling contracts and fits onto the wooden wheel
On heating the iron rim, it expands first, then on cooling it contracts and fits onto the wooden wheel.
Note: Expansion occurs on heating whereas contraction occurs on cooling.

8: (b) earthquake

9: (c) undesirable change

10: (a) evaporation