1
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
One end of string of length $$l$$ is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed '$$\upsilon $$', the net force on the particle (directed towards centre) will be (T represents the tension in the string)
A
$$T + {{m{v^2}} \over l}$$
B
$$T - {{m{v^2}} \over l}$$
C
zero
D
$$T$$
2
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will
A
move towards each other.
B
move away from each other.
C
will become stationary.
D
keep floating at the same distance between them.
3
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities $${\omega _1}$$ and $${\omega _2}$$. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is
A
$${1 \over 4}I{\left( {{\omega _1} - {\omega _2}} \right)^2}$$
B
$$I{\left( {{\omega _1} - {\omega _2}} \right)^2}$$
C
$${1 \over 8}I{\left( {{\omega _1} - {\omega _2}} \right)^2}$$
D
$${1 \over 2}I{\left( {{\omega _1} + {\omega _2}} \right)^2}$$
4
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
The acceleration due to gravity at a height at a height 1 km above the rearth is the same as at a depth d below the surface of earth. Then
A
d = 1 km
B
d = $${3 \over 2}$$ km
C
d = 2 km
D
d = $${1 \over 2}$$ km