Pick the change that can be reversed from the following.

1

(a)

Cutting of trees

(b)

Melting of ghee

(c)

Burning of candle

(d)

Blooming of flower

Which of the following changes cannot be reversed?

1

(a)

Hardening of cement

(b)

Freezing of ice cream

(c)

Opening a door

(d)

Melting of chocolate

An iron ring is heated. Which of the following statements about it is incorrect?

1

(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

While lighting a candle, Paheli observed the following changes.
(i) Wax was melting.
(ii) Candle was burning.
(iii) Size of the candle was reducing.
(iv) Melted wax was getting solidified.
Of the above, the changes that can be reversed are

1

(a)

(i) and (ii)

(b)

(ii) and (iii)

(c)

(iii) and (iv)

(d)

(i) and (iv)

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

1

(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

Rolling of chapati and baking of chapati are the changes that 

1

(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

Iran 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

(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

Which one of the steps while burning a candle is not reversible?

1

(a)

Melting of solid wax

(b)

Wax vapour burn into flame

(c)

Liquid wax changes into vapours

(d)

All of the above

Which is a way to make a change happen?

1

(a)

Heating of substance

(b)

Mixing of substance with another substance

(c)

Cooling of substance

(d)

All of the above

Rusting of iron is an example of

1

(a)

slow change

(b)

fast change

(c)

physical change

(d)

reversible change

Pick the change that can be reversed from the following:

1

(a)

Cutting of trees

(b)

Melting of ghee

(c)

Burning of candle

(d)

Blooming of flower

Which of the following changes can not be reversed?

1

(a)

Hardening of cement

(b)

Freezing of ice cream

(c)

Opening a door

(d)

Melting of chocolate

An iron ring is heated. Which of the following statements about it is incorrect?

1

(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 can not be reversed

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

1

(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 can not 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

Rolling of chapati and baking of chapati are the changes that:

1

(a)

Can be reversed

(b)

Can not be reversed

(c)

Can be reversed and can not be reversed respectively

(d)

Can not be reversed and can be reversed respectively.

Change that leads to the formation of a new substance is called

1

(a)

Chemical change

(b)

Physical change

(c)

Biological change

(d)

None of these

Grinding of grain is

1

(a)

Physical change

(b)

Chemical change

(c)

Biological change

(d)

All of these

What kind of change is the rising of Sun?

1

(a)

Physical change

(b)

Reversible change

(c)

Periodic change

(d)

Sudden change

What kind of change occurs in the eruption of a volcano

1

(a)

Physical change

(b)

Sudden change

(c)

Irreversible chang

(d)

All of these

Breaking of toy is a

1

(a)

Reversible change

(b)

Periodic change

(c)

Irreversible

(d)

All of these

Which is a way to make a change happen?

1

(a)

Heating of substance

(b)

Mixing of substance with another substance

(c)

Cooling of substance

(d)

All of the above

Rusting of iron is an example of

1

(a)

Slow change

(b)

Fast change

(c)

Physical change

(d)

Reversible change

When a chocolate melts, it is:

1

(a)

a reversible change

(b)

an irreversible change

(c)

a physical change

(d)

both (a) and (c)

A physical change is

1

(a)

Always reversible

(b)

Usually reversible

(c)

Always irreversible

(d)

None of these

When a candle is lighted, which one of the following changes is not reversible?

1

(a)

Melting of solid wax

(b)

Wax vapour burns into flame

(c)

Liquid wax changes into vapours

(d)

All of the above