Phy – Chapter 5 + Chapter 6 | Live Education Quiz

1

Why is 100% efficiency not possible in a machine?

A Because input energy is always less than output energy B Because some energy is wasted due to friction and other losses C Because output power is always greater than input power D Because machines create extra energy

2

If a machine does 100 J of work in 5 seconds, its power is:

A 20 W B 50 W C 100 W D 500 W

3

The main environmental problem caused by burning fossil fuels is:

A Ozone depletion B Global warming C Acid rain only D Noise pollution

4

A U-tube manometer is used to measure:

A atmospheric pressure only B gauge pressure of a gas C temperature of a gas D density of a liquid

5

The work-energy relation states that the work done on a body is equal to the change in its:

A Potential energy B Kinetic energy C Power D Momentum

6

The main advantage of nuclear power is:

A It produces no radioactive waste B It releases no greenhouse gases during operation C It is very cheap to build D It uses renewable fuel

7

The law of conservation of energy states that energy can be:

A Created but not destroyed B Destroyed but not created C Neither created nor destroyed D Both created and destroyed

8

The density of a material is defined as:

A mass per unit volume B force per unit area C weight per unit volume D volume per unit mass

9

In a hydroelectric power plant, the energy of flowing water is converted into:

A Chemical energy B Nuclear energy C Electrical energy D Solar energy

10

The SI unit of work is:

A Newton B Joule C Watt D Pascal

11

درج ذیل میں سے کون سا فضا کے دباؤ کا استعمال ہے؟

A سرنج کا مائع کھینچنا B اسپرنگ کا کھنچنا C گیند کا لڑھکنا D کار کا چلنا

12

The pressure due to a liquid column is independent of:

A the density of the liquid B the depth of the liquid C the acceleration due to gravity D the shape of the container

13

The limit beyond which a material does not return to its original shape is called:

A elastic limit B proportional limit C yield point D breaking point

14

Pascal's law is used in:

A Hydraulic press B Mercury barometer C Spring balance D Measuring cylinder

15

Which of the following is a social impact of using fossil fuels?

A Reduced air pollution B Health problems due to pollution C Increased crop yield D Clean water supply

16

An aneroid barometer is used to measure:

A Relative humidity B Atmospheric pressure C Wind speed D Temperature

17

بلندی بڑھنے کے ساتھ فضا کا دباؤ:

A بڑھتا ہے B کم ہوتا ہے C یکساں رہتا ہے D صفر ہو جاتا ہے

18

The work done by a force can be calculated from a force-displacement graph as:

A Slope of the graph B Area under the graph C Y-intercept of the graph D X-intercept of the graph

19

The efficiency of a machine is 80%. If the input energy is 500 J, the useful output energy is:

A 100 J B 400 J C 500 J D 625 J

20

Which of the following is the correct formula for density?

A Density = Volume / Mass B Density = Mass × Volume C Density = Mass / Volume D Density = Force / Area

21

Power is defined as the rate of doing work. Its SI unit is:

A Joule B Watt C Newton D Second

22

Efficiency of a machine is given by:

A Output energy / Input energy × 100 B Input energy / Output energy × 100 C Work / Time D Force × Distance

23

Work done by friction is:

A Positive B Negative C Zero D Always positive

24

Pascal's law states that pressure applied to an enclosed liquid is transmitted equally in all directions. Which device works on Pascal's law?

A Hydraulic press B Electric motor C Galvanometer D Telescope

25

Kinetic energy of a moving object depends on:

A Mass only B Velocity only C Mass and velocity D Height above ground