CBSE class 9 Science Objective Type Questions & Answers

21 As per the statement given in Q.9 above, What change it will take place for the potential energy of the car

A It will remain the same

B It will increase

C It will decrease

D It will becomes 3 times the Intial P.E.

Answer: It will remain the same

22 A car with mass ‘M’ is moving on horizontal road with velocity ‘v’. Driver applies accelerator and increases it speed 3 times to ‘3v’. The final K.E. acquired by the car will be :

A 4.5 Mv2

B 3.5 Mv2

C 1.5 Mv2

D 2.5 Mv2

View Answer

Answer: 4.5 Mv2

23 An external force is being applied on an object at some angle and it causes the object either to be pulled or pushed on a rough surface. Which of the following holds true ?

A It is easier to push the object

B It is easier to pull the object

C It requires same efforts to push or pull the object

D None of the above

View Answer

Answer: It is easier to pull the object

24 The value of 1 Kilo Watt Hour is

A 1.8 X 105J

B 3.6 X 106J

C 7.2 X 1010J

D None of these

View Answer

Answer: 3.6 X 106J

25 A runner, while moving, is facing a wind from the opposite direction. The work done by the wind on runner will be

A Zero

B Negative

C Positive

D Infinity

View Answer

Answer: Negative

26 The commercial unit of energy consumption in households, industries and commercial establishments is

A Joule

B Watt

C kW

D KW h (kilowatt hour)

View Answer

Answer: KW h (kilowatt hour)

27 Which of the following does not have unit as Joule?

A Force

B Potential energy

C Work done

D Kinetic energy

View Answer

Answer: Force

28 A soldier makes a swing jump between two points, by holding one end of a rope, other end of which is tied to some higher point. Work done by rope in jumping of soldier from one point to another is an example of :

A Zero work done

B Negative work

C Positive work

D None of the above

View Answer

Answer: Zero work done

29 In winters, rubbing of hands together for some time, causes a sensation of warmth mainly because of

A heat caused by the force of friction

B heat caused by the momentum

C heat caused by the motion

D heat flows from the blood to skin

View Answer

Answer: heat caused by the force of friction

30 A dog weighing 25 kg, while chasing a cat, jumps over a fence of height 1.6 m. What is the potential energy of dog at the top of fence ? (Take gravity due to earth 'g'=10 m s-2 )

A 160 Joules

B 320 Joules

C 380 Joules

D 480 Joules

View Answer

Answer: 380 Joules

31 Two objects A and B are moving with same momentum. Mass of object 'B' is greater then mass of object 'A'. Which of the two object will have higher kinetic energy?

A Object A

B Object B

C Both the objects will have same Kinetic Energy

D Object with greater mass will have higher kinetic energy

View Answer