A rubber band has more potential energy when wrapped around a packet than when it was lying unused
  • True
  • False
A ball is thrown upwards from a point A. it reaches up to the highest point B and returns.
  • Potential energy at A = kinetic energy at A
  • Kinetic energy at A = kinetic energy at B
  • Potential energy at A = potential energy at B
  • Potential energy at A = kinetic energy at B
When the speed of a particle is doubled, the ratio of its kinetic energy to its momentum
  • becomes 4 times
  • gets doubled
  • remains the same
  • becomes half
The work done by the weight of a 1-kg mass while it moves up through 1 m is
  • \(\frac{1}{9.8}J\)
  • \(-9.8J\)
  • \(-\frac{1}{9.8}J\)
  • \(9.8J\)
When a body falls, its kinetic energy remains constant.
  • True
  • False
A man with a box on his head is climbing up a ladder. The work done by the man on the box is
  • negative
  • zero
  • positive
  • undefined
When an aero plane takes off, the work done by its weight is positive.
  • True
  • False
In which of the following cases is the potential energy of a spring minimum?
  • When it is at its natural length but is kept at a height \(h\) above the ground
  • When it is compressed
  • When it is extended
  • When it is at its natural length
A particle of mass 100 g moves at a speed of 1 m/s. Its kinetic energy is
  • 50 J
  • 0.05J
  • 5 J
  • 0.5 J
Two bodies of unequal masses are dropped from a cliff. At any instant, they have equal
  • acceleration
  • Kinetic energy
  • potential energy
  • momentum
A porter with a suitcase on his head is climbing up a flight of stairs with a uniform speed. The work done by the ‘weight of the suitcase’ on the suitcase is
  • positive
  • undefined
  • negative
  • zero
When negative work is done by external forces on a system, the energy of the system decreases.
  • True
  • False
The unit of power is
  • Kg
  • Watt
  • Joule
  • Newton
The potential energy of a spring increases when it is extended and decreases when it is compressed.
  • True
  • False
A person A does \(500 \, J\) of work in 10 minutes and another person B does \(600\, J\) of work in 20 minutes. Let the power delivered by A and B be \(P_{1\) and \(P_2\) respectively. Then,
  • \(P_1=P_2\)
  • \(P_1
  • \(P_1\)and \(P_2\) are undefined
  • \(P_1>P_2\)
The number of joules contained in 1 kWh is
  • 36 × 10J
  • 3. 6 × 10J
  • 37 × 10J
  • 3. 7 × 10J
0 h : 0 m : 1 s

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