Select Page

Subject:

science-physics

Class:

class VII

Key Concepts

types of heat, transfer of heat, measurement of heat, unit of heat, heat and its effects on air, heat and its effects on various materials

essential questions

1. Why do you think we needed to find a way to measure heat?
2. Why do you think there are two types of thermometers to measure temperature?
3. Have you ever wondered why mercury has been used to show the change in temperature in a thermometer?
4. How does transfer of heat happens between states of matter?
5. How do we get heat from the sun?
6. Why is our sense of touch not reliable for measuring heat?

Remembering:

  1. Name the device used for measuring temperature: a) Thermometer  b) Ammeter  c) Anemometer d) Seismograph
  2. The unit of measurement of temperature is: a) Meter  b) Kilogram  c) Degree of Celsius  d) Second
  3. The normal temperature of human body is : a) 40° C  b) 37° C  c) 42 º C  d) 35 °C
  4.  The maximum and minimum temperature of a day are measured with a : a) Celsius thermometer b) Fahrenheit thermometer c) Maximum- Minimum Thermometer d) Kelvin Thermometer
  5. The liquid metal used in a thermometer is: a) Mercury  b silver  c) Gold  d) Copper
  6. Clinical thermometer can break: a) when kept in sun  b) when it hits a hard object c) when dipped in hot d) all of the above
  7.  Heat is : a) Form of energy b) Type of matter c) neither energy nor matter d) a form of fire

understanding:

  1.  What is the use of kink in a thermometer: a) Prevents mercury level from falling on its own  b) it raises the mercury level  c) It makes the thermometer look beautiful d) it acts as joint to the glass tube that is used for mercury and the scale.
  2.  The process by which heat flows from the hotter end to colder end of an object: a) conduction b) convection c) radiation d) vaporization
  3. The process by which transfer of heat takes place by the actual movement of particles from one part of the body to another part is called: a) conduction b) convection c) radiation d) vaporization
  4.  The transfer of heat which does not require any medium is called: a) conduction b) convection c) radiation d) vaporization
  5.  The process by whihc heat comes from sun to the earth is : a) conduction b) convection c) radiation d) vaporization
  6. In case of ____ the cool air breeze moves from land to sea: a) land breeze  b) sea breeze  c) ice breeze  d) loo
  7. Which of the following statement is or are incorrect: a) Heat is a thermal condition of a body as energy  b) Heat is the total amount of internal energy of a body  c) In the transmission of heat temperature does not remain same  d) all of the above
  8. Which of the following statement/s are correct: a) clothes of white color absorb more heat than aluminium b) Iron is better conductor of heat than aluminium c) Our body is a poor conductor of electricity d) None of the above
  9. The direction of flow of heat is: a) always from hotter body to a cooled body b) Always form cooler body to a hotter body c) Always from a body at a lower temperature to a body at higher temperature d) all of the above
  10. The flow of heat by conduction is generally observed in case of: a) solids b) Liquids c) gases d) all of these
  11. In which mode of transfer of heat occurs as a wave: a) conduction b) convection c) radiation d) all of the above
  12. One feels sensation of heat when exposed: a) ultra-voilet rays b) infra red rays c) x-rays d) Gamma rays
  13. Which of the following is a good conductor of heat: a) wood b) plastics c) aluminium d) water
  14. 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

Application:

  1. Which type of heat transfer is minimized when using a thermo flask? a) conduction b) convection c) radiation d) all of the above
  2.  Paheli wants to know is it possible to construct a building which are not affected by heat? a) building made by soil b) wooden bricks c) hollow bricks  d) white colored cement bricks
  3.  An iron ball is dropped at 40ºC in a mug of water measuring at 40º C. The heat will flow from : a) iron ball to water b) not flow from iron ball to water c) increase temperature of both. Give reasons for your answer
  4. Seema wants her noodles to cool down fast. She should put them on: a) wood b) paper c) plastic d) metal
  5. Expansion of a substance on heating depends on: a) Nature of substance b) rise in temperature c) both a and b  d) color of the substance
  6.  At times its hard to open the lid of a tight container. But when you gently heat the neck you can easily open the lid. Why:                                a) on heating glass expands more than the neck and thus slides easily. c) Neck becomes slippery on heating d) Lids of the bottles cannot bear the heat.
  7. Why stainless steel pans are generally provided with copper bottoms: a) copper bottom makes the pan more durable b) Copper bottom makes the pan appear beautiful c) copper is better conductor of heat than steel  d) copper can be cleaned more easily as compared to steel.
  8. The final temperature of a mix of water obtained by mixing equal volumes of water at 2º C and 4º C will be: a) 1 º C b) 2 º C  c) 3 º C d) 4 ºC

Analysis:

  1. On the basis of diagram answer the questions given below: Four metal cans are identical except for color and texture of thier outer surface. 100 cm³ of water at 70º C is poured into each can. Which can cools most rapidly?                                                   a) A   b) B  c) C   d) D
  2. Read the following statements carefully and choose the correct option:                                                                                                                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, statement 2 is incorrect. b) statement 2 is correct while statement 1 is incorrect. c) Both statement are incorrect. d) none of the above
  3. Read the following statements carefully and choose the correct option:                                                                                                                Statement 1: In a room containing air, heat can go from one place to other by radiation only.  Statement 2: In conduction and convection, heat is transferred from one place to other by actual motion of heated material. a) Statement 1 is correct, statement 2 is incorrect. b) statement 2 is correct while statement 1 is incorrect. c) Both statement are incorrect. d) none of the above

Evaluation:

The following questions have 2 statements as Assertion A and Reasoning R. Examine these statements carefully and decide if Assertion A and Reason R are individually true and if do whether the reason is correct.

  1. Assertion A: Heat always flows from a larger object to a smaller object. Reason R: Various modes by which heat can flow are conduction, convection and radiation. a) Both A and R are true and R is the correct  explanation of A.  b) Both A and R are true but R is not correct explanation of A. c) A is true but R is false. d) A is false but R is true.
  2. Assertion A: A clinical thermometer has a scale in the range of 37º C and 45º C. Reason R: The normal temperature of human body is 37 º C. a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not correct explanation of A. c) A is true but R is false  d) A is false but R is true.
  3. Assertion A: The flow of heat energy from one body depends upon the amount of heat energy in them. Reason R: Heat flows from lower temperature of body to higher temperature of the body.  a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not correct explanation of A. c) A is true but R is false  d) A is false but R is true.

Create: