A. Write the number of the correct answer in the brackets.
B. Write "T" for true and "F" for false.
1. The thick fur of polar bears keep them warm during winter by ________. () (1)
absorbing heat in each hair
trapping air in the fur
producing a thick layer of fats
2. When a beaker of water is stirred using a spoon for 15 minutes, the temperature of the water will ________. () (1)
be at room temperature
3. Which objects are poor conductors of heat?
(a) wire (b) rubber (c) air (d) glass
(a) and (b)
(a) and (c)
(b) and (d)
(b) , (c) and (d)
4. The constriction in a clinical thermometer ________. () (1)
prevents mercury returning to the bulb
improves thermometer sensitivity
makes the thermometer shorter
makes it easier to read the temperature
5. When damp clothes are left to dry in the sun, the moisture in clothes ________. () (1)
C. Fill in the blanks with the most suitable word.
1. All the planets in the Solar System get heat from the Sun.
() 2. The handle of a frying pan is made of plastic because plastic is a good conductor of heat.
() 3. Air expands when heated.
() 4. Nuclear reactors produce heat by chemical reaction.
() 5. The liquid inside a thermometer must be a poor conductor of heat.
1. Heat can be transferred from one object to another. Heat flows from a ____________ object to a ____________ object.
2. Heat from the Sun reaches the Earth by ____________.
3. Our sense of ____________ can tell us whether an object is hot or cold.
4. The rice-cooker converts electricity into ____________ in order to cook the rice.
5. The normal body temperature of a human being is __________.