Q.1
If the scalar product of two vectors A and  B is A⋅B =We can conclude that
  • either A = 0 or B = 0.
  • A is perpendicular to B
  • A points in the opposite direction to B.
  • A points in the same direction to B.
  • either A = 0 or B = 0 or A is perpendicular to B.
Q.2
Which of these is true of a conservative force? (more than one correct)
  • Work done between two points is independent of the path
  • Work done in a closed loop is zerocorrect
  • if the work done by the conservative is positive, its potential energy increases
  • None of the these
Q.3
If F = (60i+ 15 j- 3k) N and v = (2i- 4 j+ 5k) m/s, then instantaneous power is
  • 100W
  • 195W
  • 45W
  • 75W
Q.4
A delivery boy wishes to launch a 2.0 kg package up an inclined plane with sufficent speed to reach the top of the incline.The plane is 3 mlong and is inclined at 20°.Coefficent of friction between the package and the inclined plane is .what minimum intial KE must the boy suply to the package given as sin20°=.342 ,cos20°=.940
  • 40 J
  • 42.2 J
  • 42.6 J
  • 45 J
Q.5
A uniform chain of mass M and length L is held on a horizontal frictionless table with 1/k length hanging over the edge of the table. The work done in pulling the chain up the table
  • MgL/k
  • MgL/2k
  • MgL/k2
  • MgL/2k2
Q.6
The potential energy of a system increases if work is done
  • upon the system by a nonconservative force.
  • by the system against a conservative force.
  • by the system against a nonconservative force.
  • upon the system by a conservative force
Q.7
(a) If both assertion and reason are true and reason is the correct explanation of the assertion. (b) If both assertion and reason are true but reason is not correct explanation of the assertion. (c) If assertion is true, but reason is false. (d) If both assertion and reason are false. (e) If reason is true but assertion is false. Assertion: If momentum of a body increases by 50%, its kinetic energy will increase by 125%. Reason: Kinetic energy is proportional to square of velocity.
  • (a)
  • (b)
  • (c)
  • (d)
  • (e)
Q.8
if A= 3i + j -2 k, B= -i + 2j + 3k, C = 2i + 3j + k Then C.(A-B)
  • 0
  • 1
  • -10
  • 10
Q.9
When a long spring is stretched by 4 cm, its potential energy is U. If the spring is strethced by 20 cm, the potential energy stored in it will be
  • 2U
  • U/5
  • 5U
  • U/2
Q.10
A block of mass 10 kg is moving in x-direction with a constant speed of 10 m/s. It is subjected to a retarding force F = 0.1x joule/metre during its travel from x = 10 m to x = 20 m. Its final KE will be
  • 250 J
  • 470 J
  • 450 J
  • 485 J
Q.11
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane.it follows that (more than one correct)
  • velocity is constant
  • acceleration is constant
  • KE is constant
  • Particle moves in a circular pathcorrect
Q.12
During inelastic collision between two bodies, which of the following quantities always remain conserved?
  • Total kinetic energy.
  • Total mechanical energy
  • Total linear momentum.
  • Speed of each body
Q.13
A body is moving unidirectionally under the influence of a source of constant power supplying energy. Which of the diagrams as shown in below figure correctly shows the displacement-time curve for its motion?
work-energy-mcq-neet-1.png
  • (a)
  • (b)
  • (c)
  • (d)
Q.14
A force in the x-direction with magnitude $F = 18.0 - .530 x$ where F is in Newton and x in meter is applied to a 1.00 kg box that is sitting on the horizontal, frictionless surface of a frozen lake.If the box is initially at rest at , what is its speed after it has traveled 14.0 m?
  • 12.14 m/s
  • 14.14 m/s
  • 8.17 m/s
  • 9.1 m/s
Q.15
If the kinetic energy of a body becomes four times of its initial value, then new momentum will
  • becomes twice its initial value
  • becomes three times, its initial value
  • become four times, its initial value
  • Remains same
Q.16
A pendulum has a length L. Its bob is pulled aside from its equilibrium position through any angle $\theta$ and then released. The speed of the bob when its passes through its equilibrium position
  • $\sqrt {2gl}$
  • $\sqrt {2gl(1-cos \theta)}$
  • $\sqrt {2glcos \theta}$
  • $\sqrt {2gl(1-sin \theta)}$
Q.17
A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force is greatest
  • at the highest position of the body.
  • it remains constant all through
  • at the instant just before the body hits the earth.
  • at the instant just after the body is projected.
Q.18
A 5.00-kg block is moving at speed 5 m/s along a frictionless, horizontal surface toward a spring with force constant 500 N/m that is attached to a wall The spring has negligible mass. The maximum compression of the spring would be
work-energy-mcq-neet-2.png
  • .1 m
  • .6 m
  • .5 m
  • .4 m
Q.19
A bullet is fired from a rifle and the rifle recoils. Kinetic energy of rifle is
  • less than KE of bullet
  • greater than KE of bullet
  • equal to KE of bullet
  • None of the above
Q.20
The potential energy of a particle in a force field is $U=\frac {P}{r^2} - \frac {Q}{r}$ where P and Q are positive constants and r is the distance of particle from the centre of the field. For stable equilibrium the distance of the particle is
  • $\frac {Q}{2P}$
  • $\frac {2P}{Q}$
  • $\frac {P}{Q}$
  • $\frac {Q}{A}$
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