物理溫度、熱和內能 DSE、CE 選擇題（第 2 頁）

11.

Questions 20 and 21 : The specific heat capacity of a metal is measured using the following method :

Step 1: metal block heated in boiling water in a beaker. Step 2: block transferred to a cup of cold water with a thermometer

A metal block is first immersed in boiling water for some time. The block is then transferred to a cup of cold water. After a while, the temperature of the water is measured.

The result obtained in the last question is found to be higher than the true value of the specific heat capacity of the metal. Which of the following is a probable reason ?

12.

Copper block on a polystyrene plate with an immersion heater, thermometer and joulemeter

The apparatus shown is used to measure the specific heat capacity of a cylindrical copper block. The result of the experiment is as follows : Mass of copper block $= m$ kg Initial temperature $= 21^\circ\mathrm{C}$ Final temperature $= 47^\circ\mathrm{C}$ Initial joulemeter reading $= R_1$ J Final joulemeter reading $= R_2$ J Which of the following expressions gives the specific heat capacity of copper in $\mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$ ?

13.

Equal amount of four different liquids are separately heated at the same rate. The initial temperatures of the liquids are all $20^\circ\mathrm{C}$ . The boiling points and specific heat capacities of the liquids are shown below. Which one of the following liquids will boil first ?

Liquid	Boiling point / $^\circ$ C	Specific heat capacity / $\mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$
$P$	50	1000
$Q$	60	530
$R$	80	850
$S$	360	140

14.

An object $P$ has a higher temperature than another object $Q$ . Which of the following statements is/are correct ?

(1)The internal energy of

P

must be higher than that of

Q

.

(2)The specific heat capacity of

P

must be higher than that of

Q

.

(3)There will be a heat flow from

P

to

Q

when they are in contact.

15.

Graph of energy absorbed against temperature for liquids X, Y and Z (straight lines; X steepest, Y and Z parallel)

Equal masses of liquids $X$ , $Y$ and $Z$ are separately heated. The graph shows the variation of the energies absorbed by the liquids with their temperatures. Let $c_X$ , $c_Y$ and $c_Z$ be the specific heat capacities of $X$ , $Y$ and $Z$ respectively. Which of the following relations is correct ?

16.

Which of the following statements about internal energy, heat and temperature is/are true ?

(1)The internal energy of a body is a measure of the total kinetic energy and potential energy of the molecules in the body.

(2)Two bodies of the same temperature always have the same amount of internal energy.

(3)Heat is a measure of the energy transferred from one body to another as a result of temperature difference between the two bodies.

17.

Temperature against time graph, rising linearly from 15 degrees C at 0 s to 25 degrees C at 60 s

The graph shows the variation of the temperature of liquid with time when the liquid is heated by a $400$ W heater. The mass of the liquid is $2$ kg. Find the specific heat capacity of the liquid. Assume all the energy given out by the heater is absorbed by the liquid.

18.

The apparatus is used to find the specific heat capacity of a liquid. Which of the following can improve the accuracy of the experiment ?

(1)Take the final temperature of the liquid immediately after switching off the power supply.

(2)Cover the cup with a lid.

(3)Stir the liquid throughout the experiment.

Cup of liquid with thermometer and immersion heater connected to a power supply

19.

An heater with a power of $100$ W is used to heat $0.3$ kg of a liquid which has a specific heat capacity of $2000\ \mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$ . If the initial temperature of the liquid is $23^\circ\mathrm{C}$ , find its temperature after $2$ minutes. Assume all the energy given out by the heater is absorbed by the liquid.

20.

Which of the following phenomena concerning water can be explained by its high specific heat capacity ?

(1)Water is used as a coolant in car engines.

(2)Inland areas generally have hotter summers and colder winters than coastal areas of similar latitude and altitude.

(3)The body temperature of human beings changes slowly even when the surrounding temperature changes sharply.