Physics 11th Chap 8 : Topic 6 - Maryam Publications

Physics Chapter 8 : Topic 6

Work Done by a Gas

1 / 40

The work done when a gas expands at constant pressure is given by:

A) $\mathbf{W =}$ $\frac{\mathbf{p}}{\mathbf{\mathrm{\Delta}V}}$

B) $\mathbf{W =}$ $\frac{\mathbf{\mathrm{\Delta}V}}{\mathbf{p}}$

C) $\mathbf{W = p + \mathrm{\Delta}V}$

D) $\mathbf{W = p\mathrm{\Delta}V}$

2 / 40

In the equation $\mathbf{W = p\mathrm{\Delta}V}$, the symbol $\mathbf{\mathrm{\Delta}V}$ represents:

A) Total volume of gas

B) Change in volume

C) Final volume

D) Initial volume

3 / 40

The SI unit of work done by a gas is:

A) Pascal

B) Newton

C) Joule

D) Watt

4 / 40

The SI unit of pressure in $\mathbf{W = p\mathrm{\Delta}V}$ is:

A) $\mathbf{atm}$

B) $\mathbf{Pa}$

C) bar

D) $\mathbf{N}$

5 / 40

A gas expands against a constant pressure. The work done by the gas is:

A) Positive

B) Zero

C) Infinite

D) Negative

6 / 40

If a gas is compressed at constant pressure, the work done by the gas is:

A) Zero

B) Maximum

C) Positive

D) Negative

7 / 40

A gas expands from $\mathbf{2\ m}^{\mathbf{3}}$ to $\mathbf{5\ m}^{\mathbf{3}}$ at a pressure of $\mathbf{1000\ Pa}$. The work done is:

A) $\mathbf{7000\ J}$

B) $\mathbf{3000\ J}$

C) $\mathbf{5000\ J}$

D) $\mathbf{2000\ J}$

8 / 40

A gas expands by $\mathbf{0.02\ m}^{\mathbf{3}}$ against a pressure of $\mathbf{5 \times}\mathbf{10}^{\mathbf{4}}\mathbf{\ Pa}$. Work done is:

A) $\mathbf{100\ J}$

B) $\mathbf{1000\ J}$

C) $\mathbf{500\ J}$

D) $\mathbf{2500\ J}$

9 / 40

If there is no change in volume of a gas, the work done is:

A) Negative

B) Zero

C) Maximum

D) Minimum but not zero

10 / 40

The work done by a gas during expansion represents:

A) Change in temperature only

B) Decrease in pressure only

C) Energy transferred by the gas to surroundings

D) Increase in mass of gas

11 / 40

The area under a pressure-volume graph represents:

A) Internal energy only

B) Density

C) Work done

D) Temperature

12 / 40

On a pressure-volume graph, constant pressure is represented by:

A) A curved line

B) A vertical line

C) A horizontal line

D) A circle

13 / 40

For a gas expanding at constant pressure, increasing the volume change will:

A) Increase work done

B) Make work zero

C) Have no effect

D) Decrease work done

14 / 40

If pressure is doubled while volume change remains constant, work done:

A) Becomes half

B) Becomes zero

C) Doubles

D) Remains unchanged

15 / 40

A gas expands from $\mathbf{1\ m}^{\mathbf{3}}$ to $\mathbf{4\ m}^{\mathbf{3}}$ at $\mathbf{(2000\ Pa)}$. The work done is:

A) $\mathbf{8000\ J}$

B) $\mathbf{6000\ J}$

C) $\mathbf{2000\ J}$

D) $\mathbf{4000\ J}$

16 / 40

Which condition is necessary for using $\mathbf{W = p\mathrm{\Delta}V}$?

A) Zero pressure

B) Constant volume

C) Constant temperature

D) Constant pressure

17 / 40

During expansion of a gas, the surroundings:

A) Stop moving

B) Gain no energy

C) Receive work from the gas

D) Do work on the gas

18 / 40

A gas does $\mathbf{500\ J}$ of work while expanding at constant pressure of $\mathbf{2500\ Pa}$. The change in volume is:

A) $\mathbf{0.2\ m}^{\mathbf{3}}$

B) $\mathbf{0.1\ m}^{\mathbf{3}}$

C) $\mathbf{2\ m}^{\mathbf{3}}$

D) $\mathbf{0.5\ m}^{\mathbf{3}}$

19 / 40

If a gas is compressed, the final volume is:

A) Less than initial volume

B) Infinite

C) Equal to initial volume

D) Greater than initial volume

20 / 40

The equation $\mathbf{W = p\mathrm{\Delta}V}$ is derived from:

A) Mass $\mathbf{\times}$ acceleration

B) Energy $\mathbf{\times}$ time

C) Force $\mathbf{\times}$ displacement

D) Pressure $\mathbf{\times}$ temperature

21 / 40

Pressure is defined as:

A) Force per unit area

B) Volume per unit force

C) Energy per unit volume

D) Force $\mathbf{\times}$ area

22 / 40

A gas expands from $\mathbf{3L}$ to $\mathbf{8L}$ at $\mathbf{2 \times}\mathbf{10}^{\mathbf{5\ }}\mathbf{Pa}$. The work done is:

A) $\mathbf{1000\ J}$

B) $\mathbf{100\ J}$

C) $\mathbf{2000\ J}$

D) $\mathbf{500\ J}$

23 / 40

Work done by a gas depends on:

A) Density only

B) Temperature only

C) Mass only

D) Pressure and volume change

24 / 40

A gas expands at constant pressure. Which statement is correct?

A) No energy transfer occurs

B) Gas loses all internal energy

C) Gas transfers energy to surroundings

D) Energy is transferred from surroundings to gas as work

25 / 40

If pressure is constant and volume increases three times more than before, work done becomes:

A) One-third

B) Zero

C) Three times greater

D) Unchanged

26 / 40

A piston moves outward because gas pressure pushes it. The gas is:

A) Expanding

B) Losing particles

C) At constant volume

D) Being compressed

27 / 40

The sign convention for work done by gas during expansion is usually:

A) Positive

B) Undefined

C) Zero

D) Negative

28 / 40

A gas has pressure $\mathbf{4 \times}\mathbf{10}^{\mathbf{4}}\mathbf{\ Pa}$ and expands by $\mathbf{0.5\ m}^{\mathbf{3}}$. Work done equals:

A) $\mathbf{4 \times}\mathbf{10}^{\mathbf{5}}\mathbf{\ J}$

B) $\mathbf{2 \times}\mathbf{10}^{\mathbf{3}}\mathbf{\ J}$

C) $\mathbf{8 \times}\mathbf{10}^{\mathbf{4}}\mathbf{\ J}$

D) $\mathbf{2 \times}\mathbf{10}^{\mathbf{4}}\mathbf{\ J}$

29 / 40

If a gas expands at zero pressure, work done is:

A) Negative

B) Zero

C) Infinite

D) Positive

30 / 40

The physical meaning of $\mathbf{p\mathrm{\Delta}V}$ is:

A) Mechanical work done during volume change

B) Molecular energy

C) Temperature change

D) Heat stored in gas

31 / 40

A gas expands at constant pressure from $\mathbf{10\ m}^{\mathbf{3}}$ to $\mathbf{12\ m}^{\mathbf{3}}$. If $\mathbf{p = 500\ Pa}$, work done is:

A) $\mathbf{1000\ J}$

B) $\mathbf{5000\ J}$

C) $\mathbf{2000\ J}$

D) $\mathbf{6000\ J}$

32 / 40

Which graph gives the work done during constant pressure expansion?

A) Temperature-volume graph

B) Pressure-time graph

C) Area under $\mathbf{P - V}$ curve

D) Slope of $\mathbf{P - V}$ curve

33 / 40

A negative value of work done by gas indicates:

A) Expansion

B) Constant volume

C) Compression

D) Heating only

34 / 40

The equation $\mathbf{W = p\mathrm{\Delta}V}$ is an application of:

A) Conservation of energy

B) Conservation of charge

C) Newton’s third law only

D) Momentum law only

35 / 40

A gas absorbs heat and expands at constant pressure. Some energy is used for:

A) Stopping collisions

B) Reducing mass

C) Decreasing molecular motion

D) Doing external work

36 / 40

The unit conversion needed when volume is given in liters is:

A) $\mathbf{1\ L =}\mathbf{10}^{\mathbf{- 6}}\mathbf{\ }\mathbf{m}^{\mathbf{3}}$

B) $\mathbf{1\ L =}\mathbf{10}^{\mathbf{- 3}}\mathbf{\ m}^{\mathbf{3}}$

C) $\mathbf{1\ L =}\mathbf{1\ m}^{\mathbf{3}}$

D) $\mathbf{1\ L =}\mathbf{10}^{\mathbf{3}}\mathbf{\ m}^{\mathbf{3}}$

37 / 40

The work done by gas at constant pressure is maximum when:

A) Pressure and expansion are large.

B) Pressure is zero.

C) Gas is compressed slightly.

D) Volume change is zero.

38 / 40

The work done by a gas increases if:

A) Volume remains constant.

B) Pressure and volume change both increase.

C) Pressure becomes zero.

D) Pressure decreases and volume change decreases.

39 / 40

If $\mathbf{W = 1000\ J}$ and $\mathbf{\mathrm{\Delta}V =}\mathbf{0.5\ m}^{\mathbf{3}}$, pressure is:

A) $\mathbf{1000\ Pa}$

B) $\mathbf{2000\ Pa}$

C) $\mathbf{5000\ Pa}$

D) $\mathbf{500\ Pa}$

40 / 40

The equation $\mathbf{W = p\mathrm{\Delta}V}$ shows that work done is:

A) Always negative

B) Independent of pressure

C) Directly proportional to pressure and volume change

D) Independent of volume change

Your score is

0%