2637 + Mcqs in Science Page 31 McqOptions

1501.	Increased percentage of which gas will be present while exhaling in human beings?
A.	Carbon dioxide
B.	Oxygen
C.	Nitrogen
D.	Argon
E.	None of these
Answer» B. Oxygen

Discussion

1502.	Waste produced in liver after decomposition of unused food proteins is:
A.	Urine
B.	Blood waste
C.	Urea
D.	Carbon dioxide
E.	None of these
Answer» D. Carbon dioxide

Discussion

1503.	Lower chamber of heart includes: (i) Left atrium (ii) Left ventricle (iii) Right ventricle (iv) Right atrium
A.	(i) and (iii)
B.	(ii) and (iv)
C.	(i) and (iv)
D.	(ii) and (iii)
E.	None of these
Answer» E. None of these

Discussion

1504.	\[Glu\operatorname{cose}\to Alcohol+C{{O}_{2}}+Energy\] The above chemical reaction can take place in:
A.	Human beings
B.	Dogs
C.	Yeasts
D.	All the above
E.	None of these
Answer» D. All the above

Discussion

1505.	Animals which do not have lungs for breathing are:
A.	Grasshopper
B.	Earthworm
C.	Ant
D.	All the above
E.	None of these
Answer» C. Ant

Discussion

1506.	Which of the following statements is correct? Statement 1: Breathing is a part of respiration. Statement 2: Respiration is a part of breathing.
A.	Statement 1 is correct and statement 2 is incorrect.
B.	Statement 2 is correct and statement 1 is incorrect.
C.	Both the statement 1 and 2 are correct.
D.	Both the statement 1 and 2 are correct,
E.	None of these
Answer» B. Statement 2 is correct and statement 1 is incorrect.

Discussion

1507.	DIRECTIONS: Read the passage given below an answer the questions that follow. Passage - 1 Substances that conduct heat very well are called good conductors of heat or thermal conductors. All the metals such as silver, copper, aluminum, iron, mercury and metal alloys such as brass, steel and stainless steel are good conductors of heat. Though all the metals are good conductors of heat, some metals are better conductors of heat than the others. Among metals, silver metal is the best conductor of heat, next is copper and lowest is lead. Substances that do not conduct heat very welfare called bad conductors or poor conductors or insulators of heat. Some of the examples of heat or thermal insulators are plastic, wood, paper, cloth, thermocol, rubber, etc. Liquids like water are poor conductors and gases are very poor conductors of heat. Thus, air is a very good insulator of heat. It is observed that when glass is heated, it cracks while metal does not. Which of the following statements explain this phenomenon?
A.	Metal is a poor conductor of heat.
B.	The expansion of the glass after heating is uniform and therefore it cracks.
C.	In case of glass the heat is transmitted quickly when heated.
D.	Glass is a poor conductor of heat.
Answer» E.

Discussion

1508.	DIRECTION: Match column-I with Column-II and select the correct answer using the code given below the columns. Column - I Column - II (A) Melting (p) Solid to gas (B) Sublimation (q) Solid to liquid (C) Condensation (r) Gas to liquid (D) Vaporization (s) Liquid to gas
A.	A\[\to \] (q), B\[\to \] (p), C\[\to \] (r), D\[\to \] (s)
B.	A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s)
C.	A\[\to \] (s), B\[\to \] (p), C\[\to \] (q), D\[\to \] (r)
D.	A\[\to \] (r), B\[\to \] (s), C\[\to \] (p), D\[\to \] (q)
Answer» B. A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s)

Discussion

1509.	DIRECTION: Match column-I with Column-II and select the correct answer using the code given below the columns. Column - I Column - II (A) Range of clinical thermometer (p) \[\text{35 }\!\!{}^\circ\!\!\text{ C}\,\,\text{to 42}{}^\circ \text{C}\] (B) Range of Laboratory thermometer (q) \[-10{}^\circ C\]to \[110{}^\circ C\] (C) Normal body temperature (r) \[37{}^\circ C\] (D) A liquid metal (s) Mercury
A.	A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s).
B.	A\[\to \] (q), B\[\to \] (r), C\[\to \] (s), D\[\to \] (p)
C.	A\[\to \] (r), B\[\to \] (s), C\[\to \] (p), D\[\to \] (q)
D.	A\[\to \] (s), B\[\to \] (p), C\[\to \] (q), D\[\to \] (r)
Answer» B. A\[\to \] (q), B\[\to \] (r), C\[\to \] (s), D\[\to \] (p)

Discussion

1510.	Suppose we take two identical size rods (one wooden rod and another iron rod) and wrap each one of them in a piece of paper, and heat, these rods with a candle flame. On being heated, the paper around the iron rod does not bum but the one around wooden rod catches fire. Which of the following is the possible reason for this?
A.	Iron being a good conductor, conducts away heat given to paper.
B.	Wood being an insulator, takes away all the heat.
C.	In case of iron rod, the candle is near the paper.
D.	Paper around iron rod is thicker.
Answer» B. Wood being an insulator, takes away all the heat.

Discussion

1511.	In the process of flow of heat by conduction
A.	There is no movement of the substance
B.	The heat transfer takes place from higher temperature part of body to lower temperature part of body
C.	Occurs when one end of an iron rod is heated on a burner
D.	All the above are correct
Answer» E.

Discussion

1512.	How is heat transferred through the base of a metal saucepan?
A.	by conduction only
B.	by radiation only
C.	by conduction and convection
D.	by convection and radiation
Answer» B. by radiation only

Discussion

1513.	Temperature is a
A.	microscopic concept
B.	macroscopic concept
C.	space-time concept
D.	none of the above
Answer» C. space-time concept

Discussion

1514.	In sea breeze
A.	cold air moves from sea towards land during day time
B.	hot air moves from sea towards land during day time
C.	cold air moves from land towards sea during day time
D.	None of the above is correct
Answer» B. hot air moves from sea towards land during day time

Discussion

1515.	Read the given statements and select the correct option. Statement 1: An iron ball at \[{{35}^{o}}C\]is dropped in a mug containing water at\[305.15\text{ }K\]. Then the heat will flow from the water to the iron ball. Statement 2: In convection, heated molecules of a liquid themselves move to carry heat from the hot region to the cold region,
A.	Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B.	Both statements 1 and 2 are true and statement 2 is not the correct explanation of statement 1.
C.	Statement 1 is true but statement 2 is false.
D.	Statement 1 is false and statement 2 is true.
Answer» E.

Discussion

1516.	Why are asbestos sheets used for laying the roofs of some houses?
A.	They are good conductors of heat.
B.	They are bad conductors of heat.
C.	They are costly.
D.	They have nice look.
Answer» C. They are costly.

Discussion

1517.	A fan produces a feeling of comfort because
A.	a fan supplies cool air
B.	the evaporation of sweat
C.	fan increases the humidity in air
D.	fan decreases the humidity in air
Answer» C. fan increases the humidity in air

Discussion

1518.	A body P at a higher temperature is placed in contact with another body Q at lower temperature, till an equilibrium stage is reached. At this stage:
A.	the heat will stop flowing from P to Q
B.	the heat will stop flowing from Q to P
C.	the heat continue flowing from P to Q and vice versa
D.	None of the above
Answer» D. None of the above

Discussion

1519.	The land breeze blows from land to sea in coastal regions, because, the land:
A.	cools slowly as compared to seawater
B.	cools rapidly as compared to seawater
C.	cools at the same rate as seawater
D.	None of the above
Answer» C. cools at the same rate as seawater

Discussion

1520.	In which case rate of flow of heat form P to Q is least:
A.	\[P-100{}^\circ C,\] \[Q-40{}^\circ C\]
B.	\[P-90{}^\circ C,\] \[Q-10{}^\circ C\]
C.	\[P-50{}^\circ C,\] \[Q-10{}^\circ C\]
D.	\[P-60{}^\circ C,\] \[Q-50{}^\circ C\]
Answer» D. \[P-60{}^\circ C,\] \[Q-50{}^\circ C\]

Discussion

1521.	Why does a clinical thermometer have a range of\[35{}^\circ C-42{}^\circ C\]?
A.	To keep its size compact
B.	The temperature of human body can normally fluctuate between these two extreme ranges of lower and higher temperatures.
C.	Both the above.
D.	None of these.
Answer» C. Both the above.

Discussion

1522.	The bimetallic strip made up of aluminium and copper, when heated bends in the direction shown below. Which metal expands more when the two are heated at the same temperature?
A.	Aluminium expands more than copper.
B.	Copper expands more than aluminium.
C.	Both aluminium and copper expand by the same amount.
D.	Neither aluminium nor copper expands.
Answer» B. Copper expands more than aluminium.

Discussion

1523.	Conduction of heat does not take place in
A.	copper.
B.	iron.
C.	aluminium.
D.	vacuum.
Answer» E.

Discussion

1524.	Reflecting solar films are used on the top of the cars to:
A.	produce electricity
B.	to absorb more light
C.	to prevent heating by radiation
D.	to make to strong
Answer» D. to make to strong

Discussion

1525.	Rooms are fitted with ventilators to let the air move around. The phenomenon involved is:
A.	conduction
B.	convection
C.	radiation
D.	condensation
Answer» C. radiation

Discussion

1526.	The temperature of the substance remains constant when it is melting and boiling though some quantity of heat is supplied. What happens to this energy?
A.	It is dissipated as sound energy
B.	It is consumed to increase the energy of the molecules
C.	It is used to change the state of the substance
D.	It is still an unsolved problem in science
Answer» D. It is still an unsolved problem in science

Discussion

1527.	Gaps are left between railway tracks because:
A.	gaps give the space to the tracks to expand in summer heat
B.	gaps hold the tracks firmly
C.	to produce gentle rhythmic sound when the train moves on the track
D.	it is customary to leave the gaps
Answer» B. gaps hold the tracks firmly

Discussion

1528.	Iron glows in red color when it is heated to very high temperature because:
A.	Heat we supply assumes red color at high temperature
B.	Mechanical energy is being converted into heat energy
C.	All me fats glow in red color when heated
D.	Heat energy is being converted into light energy
Answer» E.

Discussion

1529.	We cannot use mercury thermometer at low temperatures because:
A.	glass might break down at low temperature
B.	heat does not flow from the body whose measurement we are taking with the thermometer
C.	at low temperatures mercury becomes transparent and it becomes difficult to take the readings
D.	Mercury freezes at low temperatures
Answer» E.

Discussion

1530.	The freezer in a refrigerator is fitted near the top
A.	To keep it away from the hot compressor which is near the bottom?
B.	so that it can cool the whole interior by setting up convection currents
C.	for the sake of convenience
D.	None of these
Answer» C. for the sake of convenience

Discussion

1531.	Why are two blankets warmer than one?
A.	Two blankets have more wool and hence provide greater warmth.
B.	Two blankets enclose air which does not allow the cold to penetrate.
C.	Two blankets compress the air in between the body and the blankets and this compression produces heat.
D.	None of these.
Answer» C. Two blankets compress the air in between the body and the blankets and this compression produces heat.

Discussion

1532.	One feels sensation of heat when exposed to
A.	ultra violet rays
B.	infra-red rays
C.	X-rays
D.	gamma rays
Answer» C. X-rays

Discussion

1533.	The minimum possible temperature beyond which water cannot be cooled is
A.	\[-98.5{}^\circ C\]
B.	\[100{}^\circ C\]
C.	\[-273.15{}^\circ C\]
D.	\[-469.5{}^\circ C\]
Answer» D. \[-469.5{}^\circ C\]

Discussion

1534.	Rohan wants to test whether a white object or a black object would heat up faster in the Sun. The given picture shows you his experiment. These thermometers were left out in the Sun for 30 minutes. Which of the following statements is true?
A.	Thermometer 1 reads the same as thermometer 3.
B.	Thermometer 2 shows a higher temperature than thermometer 3.
C.	Thermometer 3 shows a higher temperature than thermometer 1.
D.	Thermometer 1 reads the same as thermometer 2.
Answer» C. Thermometer 3 shows a higher temperature than thermometer 1.

Discussion

1535.	Why are two thin blankets piled together warmer than a single one of the same total thickness as the two?
A.	Air is enclosed in between them.
B.	The outer thin blanket transfers heat faster.
C.	Air acts as medium to transfer the energy.
D.	There is a decrease in the sensation of touch.
Answer» B. The outer thin blanket transfers heat faster.

Discussion

1536.	In a car, radiator and fan are used to cool the engine. The heat transfer modes involved are
A.	conduction and convection
B.	convection and radiation
C.	conduction and radiation
D.	conduction, convection and radiation
Answer» C. conduction and radiation

Discussion

1537.	A wooden spoon is dipped in a cup of ice cream. Its other end
A.	becomes cold by the process of conduction;
B.	becomes cold by the process of convection;
C.	becomes cold by the process of radiation;
D.	does not become cold.
Answer» E.

Discussion

1538.	Which one of the following will not help to cool down a cup of hot tea?
A.	Stirring the contents of cup continuously
B.	Adding a piece of ice to the cup of hot tea
C.	Pouring the hot tea in a saucer
D.	Adding more sugar to the cup of tea.
Answer» E.

Discussion

1539.	Two laboratory thermometers are marked as 'A' and 'B'. The bulb of thermometer 'A' is wrapped in a white cloth and that of thermometer 'B' in black cloth. Both the thermometers are placed in sunlight for an hour. After one hour:
A.	Both the thermometers will read the same temperature
B.	Thermometer 'A' will show higher temperature than 'B'
C.	Thermometer 'B' will show higher temperature than 'A'
D.	None of the above is correct.
Answer» D. None of the above is correct.

Discussion

1540.	When a liquid in a beaker is heated on a gas burner
A.	Heated molecules become less dense and rise
B.	Colder molecules from above move down and get heated
C.	The heat is transferred by convection
D.	All of these are correct
Answer» E.

Discussion

1541.	Four identical kettles, having the same amount of water, have bases made of different metals of same thickness. If these kettles are placed on identical flames, water will boil first in the kettle the base of which is made of
A.	Stainless steel
B.	brass
C.	Aluminum
D.	copper
Answer» E.

Discussion

1542.	Black objects are
A.	good absorbers and bad emitters of heat
B.	good absorbers and good emitters of heat
C.	bad absorbers and good emitters of heat
D.	bad absorbers and bad emitters of heat
Answer» C. bad absorbers and good emitters of heat

Discussion

1543.	One litre of water at \[30{}^\circ C\] is mixed with one litre of water at\[50{}^\circ C\]. The temperature of the mixture will be
A.	\[80{}^\circ C\]
B.	more than \[50{}^\circ C\] but less than \[80{}^\circ C\]
C.	\[20{}^\circ C\]
D.	between \[30{}^\circ C\] and \[50{}^\circ C\]
Answer» E.

Discussion

1544.	DIRECTIONS: On the basis of following diagram/picture answer the questions given below: Four metal cans are identical except for the color and texture of their outer surfaces. \[100\text{ }c{{m}^{3}}\] of water at \[70{}^\circ C\] is poured into each can. Which can cools most rapidly?
A.	A
B.	B
C.	C
D.	D
Answer» B. B

Discussion

1545.	In which mode of heat transfer does the transfer of heat occur as a wave?
A.	Conduction
B.	Convection
C.	Radiation
D.	All of these
Answer» D. All of these

Discussion

1546.	A student took an iron rod and a wooden rod and wrapped each of them in a piece of paper. These were then heated as shown. It was found that the paper around the iron rod does not burn whereas the one around the wooden rod catches fire. It is because
A.	Candle, in case of iron rod, is nearer to the paper
B.	Wood being a bad conductor of heat, takes away all the heat
C.	Iron being a good conductor of heat, conducts away the heat given to the paper
D.	Paper, in first case, is thicker.
Answer» D. Paper, in first case, is thicker.

Discussion

1547.	What is the measure of the degree of hotness or coldness of a body called?
A.	Heat energy
B.	Celsius
C.	Kelvin
D.	Temperature
Answer» E.

Discussion

1548.	DIRECTIONS: On the basis of following diagram/picture answer the questions given below: The diagram shows a vacuum flask and an enlarged view of a section through the flask wall. The main reason for the silvering is to reduce heat transfer by
A.	conduction only
B.	conduction and convection
C.	radiation only
D.	radiation and convection
Answer» D. radiation and convection

Discussion

1549.	DIRECTIONS: On the basis of following diagram/picture answer the questions given below: In the pictures shown below boxes are mad of different materials. These boxes are left in the open under the sun for an hour. After one hour which of these boxes will be hottest?
A.	(i)
B.	(ii)
C.	(iii)
D.	(iv)
Answer» E.

Discussion

1550.	DIRECTIONS: Read the following two statements carefully and choose the correct options. Statement 1: Radiation is a method of transfer of heat. Statement 2: The process of heat transfer that does not require any medium is called convection.
A.	Statement (1) is correct while statement (2) is incorrect.
B.	Statement (2) is correct while statement (1) is incorrect.
C.	Both statements are correct
D.	Both statements are incorrect.
Answer» B. Statement (2) is correct while statement (1) is incorrect.

Discussion

Explore topic-wise MCQs in 7th Class.

Increased percentage of which gas will be present while exhaling in human beings?

Waste produced in liver after decomposition of unused food proteins is:

Lower chamber of heart includes: (i) Left atrium (ii) Left ventricle (iii) Right ventricle (iv) Right atrium

\[Glu\operatorname{cose}\to Alcohol+C{{O}_{2}}+Energy\] The above chemical reaction can take place in:

Animals which do not have lungs for breathing are:

Which of the following statements is correct? Statement 1: Breathing is a part of respiration. Statement 2: Respiration is a part of breathing.

DIRECTION: Match column-I with Column-II and select the correct answer using the code given below the columns. Column - I Column - II (A) Melting (p) Solid to gas (B) Sublimation (q) Solid to liquid (C) Condensation (r) Gas to liquid (D) Vaporization (s) Liquid to gas

In the process of flow of heat by conduction

How is heat transferred through the base of a metal saucepan?

Temperature is a

In sea breeze

Why are asbestos sheets used for laying the roofs of some houses?

A fan produces a feeling of comfort because

A body P at a higher temperature is placed in contact with another body Q at lower temperature, till an equilibrium stage is reached. At this stage:

The land breeze blows from land to sea in coastal regions, because, the land:

In which case rate of flow of heat form P to Q is least:

Why does a clinical thermometer have a range of\[35{}^\circ C-42{}^\circ C\]?

The bimetallic strip made up of aluminium and copper, when heated bends in the direction shown below. Which metal expands more when the two are heated at the same temperature?

Conduction of heat does not take place in

Reflecting solar films are used on the top of the cars to:

Rooms are fitted with ventilators to let the air move around. The phenomenon involved is:

The temperature of the substance remains constant when it is melting and boiling though some quantity of heat is supplied. What happens to this energy?

Gaps are left between railway tracks because:

Iron glows in red color when it is heated to very high temperature because:

We cannot use mercury thermometer at low temperatures because:

The freezer in a refrigerator is fitted near the top

Why are two blankets warmer than one?

One feels sensation of heat when exposed to

The minimum possible temperature beyond which water cannot be cooled is

Rohan wants to test whether a white object or a black object would heat up faster in the Sun. The given picture shows you his experiment. These thermometers were left out in the Sun for 30 minutes. Which of the following statements is true?

Why are two thin blankets piled together warmer than a single one of the same total thickness as the two?

In a car, radiator and fan are used to cool the engine. The heat transfer modes involved are

A wooden spoon is dipped in a cup of ice cream. Its other end

Which one of the following will not help to cool down a cup of hot tea?

Two laboratory thermometers are marked as 'A' and 'B'. The bulb of thermometer 'A' is wrapped in a white cloth and that of thermometer 'B' in black cloth. Both the thermometers are placed in sunlight for an hour. After one hour:

When a liquid in a beaker is heated on a gas burner

Four identical kettles, having the same amount of water, have bases made of different metals of same thickness. If these kettles are placed on identical flames, water will boil first in the kettle the base of which is made of

Black objects are

One litre of water at \[30{}^\circ C\] is mixed with one litre of water at\[50{}^\circ C\]. The temperature of the mixture will be

DIRECTIONS: On the basis of following diagram/picture answer the questions given below: Four metal cans are identical except for the color and texture of their outer surfaces. \[100\text{ }c{{m}^{3}}\] of water at \[70{}^\circ C\] is poured into each can. Which can cools most rapidly?

In which mode of heat transfer does the transfer of heat occur as a wave?

A student took an iron rod and a wooden rod and wrapped each of them in a piece of paper. These were then heated as shown. It was found that the paper around the iron rod does not burn whereas the one around the wooden rod catches fire. It is because

What is the measure of the degree of hotness or coldness of a body called?

DIRECTIONS: On the basis of following diagram/picture answer the questions given below: The diagram shows a vacuum flask and an enlarged view of a section through the flask wall. The main reason for the silvering is to reduce heat transfer by

DIRECTIONS: On the basis of following diagram/picture answer the questions given below: In the pictures shown below boxes are mad of different materials. These boxes are left in the open under the sun for an hour. After one hour which of these boxes will be hottest?

DIRECTIONS: Read the following two statements carefully and choose the correct options. Statement 1: Radiation is a method of transfer of heat. Statement 2: The process of heat transfer that does not require any medium is called convection.