物理溫度、熱和內能 DSE、CE 選擇題（第 3 頁）

21.

Which of the following statements about heat is/are true ?

(1)Heat is used to describe the total energy stored in a body.

(2)Heat is used to describe the energy transferred from one body to another as a result of a temperature difference between them.

(3)A body's internal energy is increased when it is heated.

22.

An equal amount of energy is supplied to each of the following substance. Which one of them has the smallest rise in temperature ?

Substance	Mass / kg	Specific heat capacity / $\mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$
$P$	1	4200
$Q$	2	2300
$R$	3	2200
$S$	4	900

23.

Water is used as a coolant in motor car engines because

24.

An energy of $16500$ J is supplied to a metal block of mass $0.5$ kg and its rise in temperature is $64^\circ\mathrm{C}$ . The specific heat capacity of the metal is

25.

Thermometer and electric heater immersed in water in a beaker

In the diagram shown, the water is initially at room temperature. The electric heater is switched on for $300$ s and then switched off. Which of the following graphs correctly describes the variation of the reading of the thermometer ?

26.

Which of the following pairs of objects have different specific heat capacities ?

27.

The heat capacity of an object depends on its

(1)material

(2)mass

(3)shape

28.

An equal quantity of heat is supplied to each of the following substances and the corresponding rises in temperature are recorded. Which of the following substances has the smallest specific heat capacity ?

Substance	Mass (kg)	Rise in temperature ( $^\circ$ C)
$P$	2.5	5
$Q$	3.0	4
$R$	4.5	3
$S$	5.0	3

29.

When a mercury thermometer is immersed in melting ice and then in steam, the lengths of the mercury thread in the stem are respectively $2$ cm and $22$ cm. When the thermometer is put in a water bath, the length of the thread is $11$ cm. What is the temperature of the water bath ?