# JEE Main Physics Model Questions with Key

Physics is an important subject in JEE Main Examination to be conducted by JEE Board. Here we are giving important physics questions with key which can be useful for Jee Main appearing candidates.

1. The speed of liquid through the siphon is
A) 6 m/s B) 8 m/s
C) 10 m/s D) 12 m/s

2. Pressure at point B is
A) 4.25 × 104 N/m2 B) 6.25 × 104 N/m2
C) 2.50 × 104 N/m2 D) 2.0 × 105 N/m2

3. Pressure at point C is
A) 5.5 × 104 N/m2 B) 6.5 × 104 N/m2
C) 8.0 × 104 N/m2 D) 10.5 × 104 N/m2

COMPREHENSION – 2
A particle starts from rest with a time varying
acceleration a = (2t-4). Here t is in seconds
and a in m/s2. The particle moves along x-axis.

4. Particle comes to rest after a time t = …….. second
A) 1 B) 4 C) 3 D) 2

5. Maximum speed of the particle while moving in negative X-direction is at t = ……. second
A) 3 B) 4 C) 2 D) 1

6. The velocity time graph of the particle is ….
A) parabola passing through origin
B) straight line not passing through origin
C) parabola not passing through origin
D) straight line passing through origin

COMPREHENSION – 3
A small block B of mass m is kept on a circular platform which is rotating in the horizontal plane OXY. The block is at rest relative to the platform at a distance R from the centre O. At the instant shown, the block has a velocity vo j and its speed is increasing at the rate K m/s2.

COMPREHENSION – 4
It is known that if a steel ball and a feather are dropped from the same height, the steel ball falls faster than the feather. The following scientists have two different views on falling bodies.

Scientist 1 :
The force of gravity makes things fall. The greater the gravitational force on an object, the faster it falls. The steel ball falls faster because it is more massive than the feather, and thus is attracted more strongly by the earth’s gravitational
field.

Scientist 2 :
The mass of an object does not determine how fast an object falls, but shape does. Two identical pieces of paper will fall at different speeds, if one of them is crumpled into a small ball. That is because gravity is not the only force acting on a falling object. Air buoys up objects falling through it. Since the shape of the steel
ball gives it less air resistance than a feather, it falls faster.

10. According to Scientist 1, the property that determines how
fast an object will fall is its
A) chemical composition
B) mass
C) shape D) gravity

11. Suppose a small ball and a feather having the same weight are dropped from the same height. Which of the following would Scientist 1 predict?
A) The feather would fall faster than the ball
B) The ball and feather would fall at the same speed
C) The ball would fall faster than the feather
D) None of the above

12. Both scientists agree that the rate which an object falls is
affected by the
A) force of gravity
B) mass of the object
C) object’s resistance of air
D) shape of object

16. If level of liquid starts decreasing slowly when the level of liquid is at a height h1 above the cylinder, the block just starts
moving up. Then, value of h1 is

17. Let the cylinder be prevented from moving up, by applying a force and water level is further decreased. Then, height of water
level (h2 in figure) for which the cylinder remains in original position without application of force is

18. If height h2 of water level is further decreased, then
A) cylinder will not move up and remains at its
original position
B) for h2 = h 3 , cylinder again starts moving up
C) for h2 = h4 , cylinder again starts moving up
D) for h2 = h 5 , cylinder again starts moving up.

KEY: 1.C 2.A 3.B 4.B 5.C 6.A 7.D 8.B 9.D 10.B 11.B 12.A 13.B 14.D
15.D 16.C 17.B 18.A.