物理溫度、熱和內能 DSE、CE 選擇題

1.

Two liquids $X$ and $Y$ are heated by two different heaters. The energy supplied, the mass of the liquid and the temperature rises are recorded as follows.

	Liquid $X$	Liquid $Y$
Energy supplied / J	24000	18000
Mass / kg	0.3	0.2
Temperature rise / $^\circ$ C	20	25

Which of the following statements are correct ?

(1)The heat capacity of

X

is larger than that of

Y

.

(2)The specific heat capacity of

X

is larger than that of

Y

.

(3)The heat capacity of

X

determined remains the same if the experiment is repeated by doubling the mass of

X

.

2.

The figure shows the temperature-time graph of two objects $X$ and $Y$ when they are heated at the same power. Which of the following deductions are correct ?

(1)The heat capacity of

X

is smaller.

(2)If

X

and

Y

are made of the same material, the mass of

X

is smaller.

(3)The specific heat capacity of

X

is smaller.

Temperature against time lines for X (steeper) and Y, both starting from the same point

3.

Which of the following descriptions about internal energy are correct ?

(1)Different masses of water at the same temperature have the same amount of internal energy.

(2)A copper block has greater internal energy when it is hot than when it is cold.

(3)Water at

0^\circ\mathrm{C}

has greater internal energy than a block of ice of the same mass at

0^\circ\mathrm{C}

.

4.

A bottle of $0.5$ kg water and a bottle of $0.75$ kg water have been stored in a refrigerator for a few days. Which of the following statements are correct ?

(1)The temperatures of the two bottles of water are equal.

(2)The average kinetic energy of the water molecules in the two bottles is equal.

(3)The total potential energy of the water molecules in the two bottles is equal.

5.

A $100$ W immersion heater is used to heat $0.5$ kg of water, which is being stirred by a stirrer. After $3$ minutes, the water temperature increases from $25^\circ\mathrm{C}$ to $30^\circ\mathrm{C}$ . What is the estimated energy loss in this period ? Given : specific heat capacity of water $= 4200\ \mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$

Beaker of water with thermometer, stirrer and immersion heater

6.

What physical properties does the temperature of an object represent ?

(1)A measure of the degree of hotness of the object.

(2)A measure of the internal energy of the object.

(3)A measure of the average kinetic energy of the molecules of the object.

7.

Four liquids $P$ , $Q$ , $R$ and $S$ with the same mass are heated at the same rate. The graph below shows the variation of their temperatures with time.

Temperature (0 to 100 degrees C) against time (0 to 20 minutes) for liquids P, Q, R and S

Which liquid has the highest specific heat capacity ?

8.

If there is no heat flow between two bodies when in contact, then the two bodies must have the same

9.

A student uses an electric kettle to heat $0.5$ kg of water at $20^\circ\mathrm{C}$ . The water boils in $4$ minutes. Estimate the output power of the kettle. The specific heat capacity of water is $4200\ \mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$ .

10.

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 of the experiment is as follows : Mass of metal block $= 0.8$ kg Mass of water in the cup $= 0.3$ kg Initial temperature of water in the cup $= 23^\circ\mathrm{C}$ Final temperature of water in the cup $= 38^\circ\mathrm{C}$ Find the specific heat capacity of the metal (in $\mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$ ). (Given : Specific heat capacity of water $= 4200\ \mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$ .)