Worksheet solutions for chapter: Heat for class 7 are provided below.
(1) Find out conductors and insulators from the given objects:
Steel spoon, iron nail, wooden rod, plastic scale, brass scissors
Conductors: steel spoon, iron nail and brass scissors
Insulators: wooden rod and plastic scale
(2) Name the following:
(i) It is a mode of transferring heat through liquid by molecular motion. ………..
(ii) No medium is required for transfer of heat in this process. ………..
(iii) The maximum and minimum temperatures of the previous day are measured by it. …………..
(iv)Human temperature can be measured by it………….
(i) It is a mode of transferring heat through liquid by molecular motion. Convection
(ii) No medium is required for transfer of heat in this process. Radiation
(iii) The maximum and minimum temperatures of the previous day are measured by it. Maximum – minimum thermometer
(iv) Human temperature can be measured by it. Clinical thermometer
(3) Write precautions to handle the clinical thermometer.
Precautions to use a clinical thermometer
(i) Thermometer should be washed before and after use, preferably with an antiseptic solution.
(ii) Ensure that before use the mercury level is below 350C.
(iii) Read the thermometer keeping the level of mercury along the line of sight.
(iv) Handle the thermometer with care. If it hits against some hard object, it can break.
(v) Don’t hold the thermometer by the bulb while reading it.
(4) Define land breeze.
Ans- Land breeze is the cool air above the land which moves towards the sea to replace the hot air above the sea.
(5) The windows of the houses of in coastal areas are made to face to sea. Give reason.
Ans- The windows of the houses in coastal areas are made to face to sea to receive the cooler sea breeze. Sea breeze is the cool air above the sea which moves towards the land to replace the hot air above the land.
(6) Fill in the blanks:
(i)….. is the lowest body temperature for humans.
(ii)No ………. is required in transferring heat in radiation.
(iii)Wood is a good …………of heat.
(iv)…………….thermometer does not has mercury.
(i) 35oC is the lowest body temperature for humans.
(ii) No medium is required in transferring heat in radiation.
(iii) Wood is a good insulator of heat.
(iv) Digital thermometer does not have mercury
(7) Identify the pictures given below:
(a) Clinical thermometer
(b) Digital thermometer
(8) Define heat and write names of different ways in which heat can flow from one object to another.
Ans- Heat is transfer of energy from hotter body to colder body.
Names of different ways in which heat can flow from one object to another are given below:
(9) What is temperature? Name the instrument with which we can measure the temperature.
Ans- Temperature is a reliable measure of the hotness of an object. It is measured in oC.
Temperature is measured by a device called thermometer.
(10) Identify the pictures showing different mode of transferring heat.