CBSE CLASS 9 CHAPTER Q/A -WORK ENERGY & POWER

CBSE MCQ Questions with answers can be used most effectively to measure both simple knowledge and complex concepts. Since multiple-choice questions can be answered quickly, they can assess a students' mastery of many topics in a short period of time.

Correctly structured CBSE MCQ Quiz that offers the greatest academic value will not simply indicate if the student’s answer is right or wrong, it will go further by clearly explaining the reasons why each answer was right or wrong – thus ensuring the all-important continuation of the learning process.

We have also added CBSE NOTES FOR QUICK REVISION , Which help you to focus your attention and avoid distractions. As you read notes, you will be engaging your mind in identifying and organizing the main ideas of topic in minimum time span and make it easy to memorize the topic for best result.

 

Q1:Define work ?

 

   

Answer: Work is the displacement of an object when a force (push or pull) is applied to it.

 

 

Q2:What is SI unit of work?

 

   

Answer: Joule

 

 

Q3: Define 1  joule?

 

   

Answer: if a force of 1N displaces an object for displacement of 1m in direction of applied force then workdone by the force is 1 joule.

 

 

Q4: What is the kinetic energy of an object?

 

   

Answer: The energy possessed by a body by virtue of its motion is called kinetic energy

 

 

Q5: What is  Work done on a body moving in circular path .

 

   

Answer: Zero

 

 

Q6:What is computation formula  of work done by a constant force F acting on body and undergoes a displacement of d .

 

   

Answer: W= F.d

 

 

Q7:  When force acting on the body is perpendicular to the direction of the displacement of the body. What is the work done  ?

 

   

Answer: Zero.

 

 

Q8:What is called ability to do work ? 

 

   

Answer:  Energy

 

 

Q9: What is called the energy possessed by a body due to its position ?

 

   

Answer: Potential energy

 

 

Q10:   A body of mass m moving with a speed v has kinetic energy, Ek. The body  if moves with speed 2v, what will have kinetic energy ?

 

   

Answer:  4Ek

 

 

Q11: A body of mass m moving with a speed v has kinetic energy Ek. A body of mass 2m moving with the same speed will have a kinetic energy  ?

 

   

Answer: 2Ek

 

 

Q12: A ball of mass 0.5 kg has100 J of kinetic energy. What is the velocity of the ball ?

 

   

Answer: 20 ms^-2

 

 

Q13:   Two bodies of equal mass move with uniform velocities u and 4 u respectively. Find the ratio of their kinetic energies ?

 

   

Answer:1:16

 

 

Q14:   Kamya climbs up a staircase in 5 minutes, Suraiya takes only 3 minutes in going up the same staircase. The weight of Kamya is equal to the weight of Suraiya. Which of the two does more work? ?

 

   

Answer: Both has done equal work

 

 

Q15:   Kamya climbs up a staircase in 5 minutes, Suraiya takes only 3 minutes in going up the same staircase. The weight of Kamya is equal to the weight of Suraiya.Which of the two does  have more power ?

 

   

Answer: Suraiya has more power .