Chapter 6: Changes Around Us
Choose the correct answer,
Q1. Which of the following is not a man-made change?
(a) Change of day and night
(b) Burning of fuels
(c) Drying of clothes
(d) Tearing of paper
Answer
Answer: (a) Change of day and night
Q2. Which of the following is a chemical change?
(a) Evaporation of water
(b) Burning of fuels
(c) Moving of a wheel
(d) Breaking of a brick
Answer
Answer: (b) Burning of fuels
Q3. Rusting of iron is an example of
(a) slow change
(b) fast change
(c) reversible change
(d) physical change
Answer
Answer: (a) slow change
Q4. Conversion of a solid to liquid by heating is called
(a) evaporation
(b) melting
(c) condensation
(d) freezing
Answer
Answer: (b) melting
Q5. Which of the following changes can be reversed?
(a) Raw egg to boiled egg
(b) Wet clothes to dry clothes
(c) Bud to flower
(d) Cow dung to biogas
Answer
Answer: (b) Wet clothes to dry cloth
Q6. Which of the following changes cannot be reversed?
(a) Milk to paneer
(b) Cold milk to hot milk
(c) Yam to knitted sweater
(d) Wet clothes to dry clothes
Answer
Answer: (a) Milk to paneer
Q7. Metal rim is fixed to the wooden cart wheel by
(a) heating metal rim
(b) heating wooden wheel
(c) cooling metal rim
(d) cooling wooden wheel
Answer
Answer: (a) heating metal rim
Q8. On heating metal rim
(a) expands
(b) contracts
(c) depends how much it is heated
(d) depends as the type of meted
Answer
Answer: (a) expands
Q9. Which one of the steps while burning a candle is not reversible?
(a) Melting of solid wax
(b) liquid wax changes into vapours
(c) Wax vapour bums into flame
(d) All of these
Answer
Answer: (c) Wax vapour bums into flame
Q10. Which is a way to make a change happen?
(a) Heating a substance
(b) Cooling a substance
(c) Mixing a substance with another substance
(d) All of these
Answer
Answer: (d) All of these