# Ncert Exemplar Solutions Class 7 Science Heat

## Ncert Exemplar Solutions Class 7 Science Heat

Welcome to NCTB Solutions. Here with this post we are going to help 7th class students for the Solutions of NCERT Exemplar Class 7 Science Book, Unit 4, Heat. Here students can easily find step by step solutions of all the problems for Heat, Also here our Science teacher’s are solved all the questions with easily understandable language with proper guidance so that all the students can understand easily.

Heat all Question Solutions :

Multiple Choice Questions :

Question no – (1)

A marble tile would feel cold as compared to a wooden tile on a winter morning, because the marble tile

Correct option (a)

Because the marble tile is a better conductor of heat than the wooden tile.

Question no – (2)

A beggar wrapped himself with a few layers of newspaper on a cold winter night. This helped him to keep himself warm because

Correct option (b)

This helped him to keep himself warm because air trapped between the layers of newspaper is a bad conductor of heat.

Question no – (3)

Paheli and Boojho measured their body temperature. Paheli found her’s to be 98.6 °F and Boojho recorded 37°C. Which of the following statement is true?

Correct option (c)

The correct statement is Both have normal body temperature.

Question no – (4)

Boojho has three thermometers as shown in Figure 4.1. He wants to measure the temperature of his body and that of boiling water. Which thermometer (s) should he choose?

Correct option is (a)

(a) Thermometer (i) or (iii) for measuring body temperature and (ii) for measuring the temperature of boiling water.

Question no – (5)

Four arrangements to measure temperature of ice in beaker with laboratory thermometer are shown in Figure 4.2 (a, b, c and d). Which one of them shows the correct arrangement for accurate measurement of temperature?

Correct option is (a)

Figure (a) shows the correct arrangement for accurate measurement of temperature.

Question no – (6)

Fig 4.3 (a–d) shows a student reading a doctor’s thermometer. Which of the figure indicates the correct method of reading temperature?

The appropriate option is – (a)

Figure – (a) indicates the correct method of reading temperature.

Question no – (7)

Figure 4.4. (a – d) shows the readings on four different thermometers. Indicate which of the reading shows the normal human body temperature?

Correct answer is option – (c)

Figure – (c) shows the normal human body temperature.

Question no – (8)

Shopkeepers usually keep ice blocks in jute sacks as jute is a bad conductor of heat so it keeps the heat away from the ice, which keeps ice safe from melting.

Question no – (9)

The thermometer A will show much temperature as the thermometer is kept above the candle, the air gets heated up and it reaches the thermometer above through convection.

Question no – (10)

Yes, she can apply the same method to keep a glass of cold drink cool. Since the woolen cloth is a bad insulator it will keep away the surrounding heat from heating up the drink.

Question no – (11)

In a mercury thermometer, the level of mercury rises after coming in contact with a hot object because mercury expands when heated and since it expands in a tube it has nowhere to go but up.

Question no – (12)

(i) The heat will flow from O to P as well as O to R.

(ii) The pins at P and R will fall at the same time while the pin at Q will fall at the last.

Question no – (13)

The pins in both the cases are likely to fall at different paces because in figure B the pin Q will fall first followed by pin P since the heat reaches pin Q first while in figure A both the pins fall at the same time as heat reaches them at the same time.

Question no – (14)

The container in which the curd is mixed with the milk should be covered with a bad conductor of heat to keep the temperature maintained or it could be kept it the sun or the mixture could be kept in a heat resistant container to keep away the heat from escaping.

Question no – (15)

Before using a clinical thermometer few sharp jerks are given to the thermometer so that the mercury in the kink or above it will fall back to the bulb so that the mercury level will be below normal temperature and it will help taking the measurements correctly.

Question no – (16)

It is advised not to hold the temperature by its bulb at the time of reading since the mercury in it could expand by our body temperature and could gives us incorrect readings.

Question no – (17)

On a hot summer day I would prefer the tent made of white fabric since white colour is a bad absorber of heat and a good reflector of heat. So it would it be quite comfortable to rest in it.

During winter I would not prefer the same tent but rather the black one because black is a good absorber of heat so it will absorb the heat and keep me warm.

Question no – (18)

The windows of the houses in the coastal areas should be placed in such a way that it faces the sea this will keep the houses cool by letting the cool see breeze enter the house.

Question no – (19)

(i) Which position P or T will feel warmer?

= The hand at position P will feel much warmer due to the hot air rising up due to convection.

(ii) Fill up the boxes P and T to indicate the mode of flow of heat to the hand.

Position P – Convection is the process of heat transfer.

Position T – Radiation is the process of heat transfer.

Question no – (20)