Blow Hot, Blow Cold - 1 Class 5 Worksheet EVS Chapter 15

Q1: Multiple Choice Questions (MCQs)

(i)What does the woodcutter blow on to warm them up?
(a)His feet
(b) His hands
(c) The fire
(d) The potatoes

Ans: (b) 
The woodcutter blows on his hands to warm them up because they are cold from the winter air.

(ii) Why did the woodcutter blow on the fire?
(a) To make it hotter
(b) To cool it down
(c) To put it out
(d) To keep warm

Ans: (a) 
The woodcutter blows on the fire to intensify it, helping the damp wood catch fire more effectively for cooking his meal.

(iii) What did Mian Balishtiye think the woodcutter was?
(a) A man
(b) A ghost
(c) A tree
(d) A djinn

Ans:(b) 
Mian Balishtiye was puzzled by the woodcutter's ability to blow hot and cold air, leading him to wonder if the woodcutter was a supernatural being like a ghost or djinn.

(iv) What did the woodcutter do when he took out the potato from the pot?
(a) He ate it immediately
(b) He blew on it to cool it down
(c) He threw it away
(d) He gave it to Mian Balishtiye

Ans: (b)
The woodcutter, finding the potato too hot to eat, blew on it to cool it down before eating.

(v) Suppose you are given hot khichdi to eat. How will cool down without blowing air from your mouth?
(a) By mixing cold water into it.
(b) By spreading it over the plate.
(c) By putting ice cubes into it.
(d) By spreading it over our palm.

Ans: (b) 
Spreading the hot khichdi over the plate increases its surface area, allowing it to cool down more quickly through heat dissipation to the surrounding air.

(vi) Suppose you bang your head while playing and your forehead is swollen, a warmed handkerchief if put over it gives relief. Why is it so?
(a) Warm air kills germs on the injury.
(b) Handkerchief has medicine on it.
(c) Warm air soothes the skin giving relief.
(d) It is done to please children.

Ans: (c)
Applying a warm handkerchief to a swollen area can help soothe the skin and reduce discomfort, as the warmth can promote blood flow and ease pain.

Q2: Match the Following

Answer: 

Q3: Short Answer Questions

(i) What did the woodcutter do to warm his cold hands?

Ans: The woodcutter blew on his cold hands to warm them up. This helped him feel better in the cold winter.

(ii) Why did the woodcutter blow on the hot potato?

Ans: The woodcutter blew on the hot potato to cool it down because it was too hot to eat. Blowing on it made it safe to eat.

(iii) What did Mian Balishtiye think when he saw the woodcutter blowing on his hands and food?

Ans: Mian Balishtiye was confused. He thought the woodcutter might be a ghost because he could blow hot and cold air with the same breath.

(iv) How did the woodcutter feel when he was cutting wood in the forest?

Ans: The woodcutter felt cold because it was winter, and his fingers were becoming numb. He needed to warm them up.

(v) What happened when Mian Balishtiye saw the woodcutter blowing on the fire?

Ans: Mian Balishtiye was surprised and thought the woodcutter was blowing fire. He wondered why the woodcutter was blowing so much.

(vi)  Why do we blow on hot tea to cool it?

Ans: Blowing on hot tea increases the rate of evaporation by removing the hot vapours from the surface, thus cooling it down more quickly.

(vii) Why does the paper snake move in a clockwise direction when placed near a hot object?

Ans: The air near the hot object becomes warm and rises, causing the paper snake to rotate in a clockwise direction due to the upward flow of hot air.

 True- Life Application Based Questions

(i) How can blowing air help keep you warm in winter and cool in summer at home?Answer: In winter, when your hands feel very cold, just like the woodcutter, you can warm them by blowing warm breath on them. In summer, if your soup or porridge is too hot to eat, blowing cool air over it can help it cool down faster so it's comfortable to eat.

(ii)  How can blowing on your food help when you pack a picnic?Answer: If you have hot food like pasta or chicken that you want to take to a picnic, it’s a good idea to let it cool down first so it doesn't spoil. Blowing gently on the food helps it cool quicker, and then you can pack it in your picnic basket.

(iii) Why is it good to know about hot and cold air when you're cooking or using things like ovens at home?Answer: When you use an oven to bake cookies or a cake, knowing how hot air moves around helps you place your tray in the right spot so everything cooks evenly. If you understand that hot air rises, you'll know that placing food in the middle rack usually works best.

(iv) How does blowing on your hands like the woodcutter teach us about dressing warmly for outdoor winter fun?Answer: Blowing on your hands is a quick way to get a little warmth, just like the woodcutter did. However, when you go outside to play in the snow or cold weather, wearing gloves is much better because they keep your hands warm all the time, not just when you blow on them.

(v) What should you remember about blowing air when starting a barbecue or campfire safely?Answer: When starting a barbecue or a campfire, it’s important to blow gently to help the fire start without blowing too hard, which might send ashes and sparks flying dangerously. It’s like helping the fire breathe and grow slowly and safely.