Home
Class 12
PHYSICS
Select the correct alternative....

Select the correct alternative.

A

Work done by kinetic friction on a body always results in a loss of its kinetic energy.

B

Work done on a body, in the motion of that body over a close loop is zero for every force in nature.

C

Total mechanical energy of a system is always conserved no matter what type of internal and ecternal forces on the body are present.

D

When total work done by a conservative force on the system is positive then the potential energy associated with this force decreases.

Text Solution

Verified by Experts

The correct Answer is:
D
`N//A`
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

in which of the following cases the centre of mass of a rod is certainly not at its centre? (A) The density continuously increases from left ot right (B) The density continuously decreases from left to right (C) The density decreases from left to right up to the centre and then increases (D) The density increases from left to right up to the centre and then decreases Select correct alternative.

A 1 Kg solid sphere rolls without slipping on a rough horizontal suface as shown in figure. Select incorrect alternative

a projectile is thrown with speed u into air from a point on the horizontal ground at an angle theta with horizontal. If the air exerts a constant horizontal resistive force on the projectill then select correct alternative(s).

A projectile is thrown with speed u into air from a point on the horizontal ground at an angle theta with horizontal. If the air exerts a constant horizontal resistive force on the projectile then select correct alternative(s).

Potential energy curve U of a particle as function of the position of a particle is shown. The particle has total mechanical energy E of 3.0 joules. Then select correct alternative.

Choose the correct alternatives.

Consider following statement (A) Work done by pseudo force in non-inertial frame itself cannot be positive (B) Net work done by static friction on the system (consisting surfaces I contact) is always zero (C) Net work done by Kinetic friction on the system (consisting surfaces in contact) may be positive (D) Work done by kinetic friction on a body may be positive Select correct alternative :-

A ball A moving with a velocity 5 m/s collides elastically with another identical ball at rest such that the velocity of A makes an angle of 30^(@) with the line joining the centres of the balls. Then consider following statements : (A) Balls A an B move at right angles after collision (B) kinetic energy is conserved (C) speed of A after collision is (5/2) m/s (D) speed of B after collision is ( 5sqrt(3)//2 ) m/s Select correct alternative :-

ALLEN -TEST PAPER-Exercise (Physics)
  1. A body of mass 0.5 kg travels in a straight line with velocity v = ax^...

    Text Solution

    |

  2. One end of a light spring of spring constant k is fixed to a wall and ...

    Text Solution

    |

  3. Select the correct alternative.

    Text Solution

    |

  4. A constant force produces maximum velocity V on the block connected to...

    Text Solution

    |

  5. A particle with total energy E moves in one dimensional region where t...

    Text Solution

    |

  6. In the figure, block A is released from rest when the spring is its na...

    Text Solution

    |

  7. A body of mass 2.0 kg, force to travel in the x-direction, is subjecte...

    Text Solution

    |

  8. The potential energy for a force filed vecF is given by U(x,y)=cos(x+y...

    Text Solution

    |

  9. A particle of mass 5kg moving in the X-Y plane has its potential energ...

    Text Solution

    |

  10. As a particle moves along the x-axis, it is acted upon by a conservati...

    Text Solution

    |

  11. Water is flowing in a river at 2 ms^(-1). The river is 50 m wide and h...

    Text Solution

    |

  12. Which of the following statemente is / are INCORRECT? (a) Mechanical...

    Text Solution

    |

  13. Consider the following sketch of potential energy for a particle as a ...

    Text Solution

    |

  14. The potential energy of a 1 kg particle free to move along the x- axis...

    Text Solution

    |

  15. The figure below shows a graph of potential energy U(x) verses positio...

    Text Solution

    |

  16. A force F acting on a body depends on its displacement x as Fpropx^(a)...

    Text Solution

    |

  17. If vec(A)=2hat(i)+hat(j)+hat(k) and vec(B)=hat(i)+2hat(j)+2hat(k), fi...

    Text Solution

    |

  18. An insect starts from (2,3,4) and travels along (hat(i)+2hat(j)+2hat(k...

    Text Solution

    |

  19. For the given vector vec(A)=3hat(i)-4hat(j)+10hat(k), the ratio of mag...

    Text Solution

    |

  20. In the arrangement shown in figure coefficient of friction between 5kg...

    Text Solution

    |