Olympiad Test: Heat - Grade 7 MCQ

Heat transfer in steel rod is by the process of conduction because in metal heat transfer occurs by conduction.

With increase in heat energy the particles of matters start vibrating faster that increase the temperature of the body.

those substances that do not conduct heat are called insulator. Copper, aluminium and graphite is conductor but air is insulator.

Normal body temperature is about 37⁰C which may vary with person to person.

Wooden spoon is poor conductor of heat so; a wooden spoon dipped in cup of ice-cream does not become cold.

The bottom of stainless steel pan has copper as copper is better conductor of heat to cook the food faster.

Heat is a form of energy that gives feeling of hotness or coldness.

Metals are best conductor of heat. Metal transfers the heats by conduction in which particles are close to each other.

Kelvin = Celsius + 273. So, 10⁰C is equal to 10+273 =283K.

Cotton clothes are preferred in summer because cotton clothes absorb sweats and make us more comfortable.

During day time near costal area wind blows from land to sea called land breeze.

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

In thermometer mercury is used because it do not stick with wall of container, have shiny appearance and expand uniformly on heating.

Kelvin = 273 + Celsius, hence, 25⁰C = 273+ 25 = 298K .

Liquid and gas transfer the heat by the process of convection. The hotter molecules in contact of hot object heat up and move upward to transfer the heat.

Metals are good conductor of heat as the particle of metals are in contact of each other to transfer the heat by conduction.

Woollen clothes keep us warm in winter because air trapped between threads act as insulator to prevent heat loss of the body.

Temperature changes with increase in energy.

Sun’s light reaches to earth surface through radiation as no medium is available from sun to earth to conduct heat.

The temperature at which pure water start changing into water vapour is called boiling point. Boiling point of pure water is 100⁰C.