50 solutions available
Question 1The temperature of a body rises by 1°C. What is the corresponding rise on the:(a) Fahrenheit scale(b) Kelvin scale?
Question 2The temperature rises by 18°F. What is the rise on the Celsius scale?
Question 3Convert 5°F to the Celsius scale.
Question 4Convert 40°C to the:(a) Fahrenheit scale(b) Kelvin scale
Question 5Convert -40°F to the Celsius scale.
Question 4gThe vacuum kept in between the walls of a thermos flask reduces the heat transfer by:conduction onlyconvection onlyradiation...
Question 6What is the Fahrenheit scale of temperature?
Question 7What is the Kelvin scale of temperature?
Question 8How are the Celsius and Fahrenheit scales inter-related?
Question 9How is the size of a degree defined on a Celsius scale?
Question 11State the temperature of:(i) ice point(ii) steam point, on the Celsius scale.
Question 12Write down the temperature of:(i) lower fixed point(ii) upper fixed point, on the Fahrenheit scale.
Question 13The figure shows a glass tumbler containing hot milk which is placed in a tub of cold water. State the direction in which heat will flow.
Question 14Draw a neat labelled diagram of a laboratory thermometer.
Question 15Write down the body temperature of a healthy person?
Question 16What do you understand by thermal expansion of a substance?
Question 17Name two substances which expand on heating.
Question 18Why do telephone wires sag in summer?
Question 19Iron rims are heated before they are fixed on the wooden wheels. Explain the reason.
Question 20Why are gaps left between successive rails on a railway track?
Question 21A glass stopper stuck in the neck of a bottle can be removed by pouring hot water on the neck of the bottle. Explain why?
Question 22Why is a cement floor laid in small pieces with gaps in between?
Question 23One end of a steel girder in a bridge is not fixed, but is kept on rollers. Give the reason.
Question 24Describe one experiment to show that liquids expand on heating.
Question 25State one application of thermal expansion of liquids.
Question 26Describe an experiment to show that air expands on heating.
Question 27An empty glass bottle is fitted with a narrow tube at its mouth. The open end of the tube is kept in a beaker containing water. When the...
Question 28State which expands more, when heated to the same temperature: solid, liquid or gas?
Question 29Name the three modes of transfer of heat.
Question 30Name the mode of transfer of heat in the following:(a) solid(b) liquid(c) gas(d) vacuum.
Question 31What are good and bad conductors of heat? Give two examples of each.
Question 32Name a liquid which is a good conductor of heat.
Question 33Name a solid which is a good conductor of heat.
Question 34Select good and bad conductors of heat from the following:copper, mercury, wood, iron, air, saw-dust, cardboard, silver, plastic, wool.
Question 35Why is an oven made of double walls with the space in between filled with cork?
Question 36Why do we use cooking utensils made up of copper?
Question 37Why is a tea kettle provided with an ebonite handle?
Question 38In summer, ice is kept wrapped in a gunny bag. Explain the reason.
Question 39Explain why:(a) we wear woollen clothes in winter?(b) the water pipes are covered with cotton during very cold weather?
Question 40Why are quilts filled with fluffy cotton?
Question 41State the direction of heat transfer by way of convection.
Question 42Why is a ventilator provided in a room?
Question 43Why are chimneys provided over furnaces in factories?
Question 44What are land and sea breezes? Explain their formation.
Question 45Why is the freezing chest in a refrigerator fitted near its top?
Question 46Explain briefly the process of heat transfer by radiation.
Question 47Give one example of heat transfer by radiation.
Question 48Why do we prefer to wear white or light coloured clothes in summer and black or dark coloured clothes in winter?
Question 49The bottom of a cooking utensil is painted black. Give the reason.
Question 50Draw a labelled diagram of a thermos flask. Explain how the transfer of heat by conduction, convection and radiation is reduced to a...