The term used to mention study of macroscopic system to microscopic constituents is _____________.

(a)

unification

(b)

macrocosm

(c)

reductionism

(d)

microcosm

In equation of motion S = ut+\(1\over 2\)kt² the dimensional formula for K is______________

(a)

[L T^-1]

(b)

[L T^-2]

(c)

[T]

(d)

[L^-1 T]

When a body undergoes an oblique projection, maximum range of it is ____________.

(a)

\(\frac{u^2}{g}\)

(b)

\(\frac{u}{g}\)

(c)

\(\frac{u^2}{g^2}\)

(d)

\(\frac{u^2}{2g}\)

Two cars P and Q start fun a point at the same time in a straight line and their positions are represented by X p(t) = (at + bt²) and x_Q(t) = (ft - ft²). At what time do the cars have the same velocity?

(a)

\({a-f\over l+b}\)

(b)

\({a+f\over2(b-1)}\)

(c)

\({a+f\over2(l+b)}\)

(d)

\({f-a\over2(b-1)}\)

A body is projected vertically upward with the velocity v = \(3\hat{i}+4\hat{j} \ ms^{-1}\). The maximum height attained by the body is __________ (g = 10 ms^-2)

(a)

7 m

(b)

1.25 m

(c)

8 m

(d)

0.08 m

Twelve forces each of magnitude 10N acting on a body at an angle of 30° with other forces then their resultant is __________.

(a)

10 N

(b)

120 N

(c)

\(\frac{10}{\sqrt{3}}\)

(d)

zero

A vehicle is moving along the positive x direction, if sudden brake is applied, then

(a)

frictional force acting on the vehicle is along negative x direction

(b)

frictional force acting on the vehicle is along positive x direction

(c)

no frictional force acts on the vehicle

(d)

frictional force acts in downward direction

Three forces F₂, F₂ & F₃ are acting on a particle of mass m such that F₂ & F₃ are mutually perpendicular, then the particle remains stationary. If the force F₁ is now removed, then the acceleration of the particle is _____________.

(a)

\(\frac { { F }_{ 1 } }{ m } \)

(b)

\(\frac { { F }_{ 2 }{ F }_{ 3 } }{ mF } \)

(c)

\(\frac { { F }_{ 2 }-{ F }_{ 3 } }{ m } \)

(d)

\(\frac { { F }_{ 2 } }{ m } \)

The force required to stop a moving object depends on its ____________.

(a)

mass alone

(b)

velocity alone

(c)

mass or velocity

(d)

mass and velocity

If the tension in the cable of 1000 kg elevator is 1000 kg weight, then the elevator _____________.

(a)

is accelerating upwards

(b)

is accelerating downwards

(c)

may be at rest or accelerating

(d)

may be at rest or in uniform motion

Which of the following is the dimension of coefficient of friction?

(a)

[MLT^-2]

(b)

[M⁰L⁰T⁰]

(c)

[M²LT^-2]

(d)

[M²LT]

A boy presses a book against the front wall such that the book does not move. The force of friction between the wall and the book is _______________.

(a)

towards right

(b)

towards left

(c)

downwards

(d)

upwards

When a car is turning around a corner, the person sitting inside the car ________________.

(a)

may fall down

(b)

experiences a force

(c)

experiences an inward force

(d)

experiences outward force

A lift is moving down with an acceleration of 4.9 ms^-2. The percentage change in the weight of a person in the lift is ______________.

(a)

75%

(b)

50%

(c)

25%

(d)

12.5%

A bag of sand of mass 'm' is suspended by a rope. A bullet of mass \(\left( \frac { m }{ 20 } \right) \) is fired at it with a velocity V and gets embedded in it. The final velocity of the bag is ______________.

(a)

\(\frac { 21V }{ 20 } \)

(b)

\(\frac { V }{ 21 } \)

(c)

\(\frac { V }{ 20 } \)

(d)

\(\frac { 20 }{ 21 } V\)

Two stones of masses m and 2m are whirled in horizontal circles, the heavier one in a radius \(\frac { r }{ 3 } \) and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier. stone when they experience same centripetal forces. The value of n is _______________.

(a)

4

(b)

1

(c)

2

(d)

3

A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/s. A bob is suspended from the roof of the car by a light wire of length 1.0 m. The angle made by the wire with the vertical is ______________.

(a)

\(\frac { \pi }{ 3 } \)

(b)

\(\frac { \pi }{ 6 } \)

(c)

\(\frac { \pi }{ 4 } \)

(d)

0⁰

The mass of a lift is 2000 kg. When the tension in the supporting cable is 28000 N, then its acceleration is _______________.

(a)

4 ms^-2 upwards

(b)

4 ms^-2 downwards

(c)

14 ms^-2 upwards

(d)

30 ms^-2 downwards

A lift of mass 1000 kg which is moving with the acceleration of 1 m/s² in the upward direction, then the tension developed in the string which is connected to lift is _________________

(a)

9800 N

(b)

10,800 N

(c)

11,000 N

(d)

10,000 N

Two masses as shown in the figure are suspended from a massless pulley. The acceleration of the system when masses are left free is ______________.

(a)

\(\frac { 2g }{ 3 } \)

(b)

\(\frac { g }{ 3 } \)

(c)

\(\frac { g }{ 9 } \)

(d)

\(\frac { g }{ 7 } \)

A mass M is placed on a very smooth wedge resting on a surface without friction. Once the mass is released, the acceleration to be given to the wedge so that M remains at rest is a where ______________.

(a)

a is applied to the left and a = gtan θ

(b)

a is applied to the right and a = gtan θ

(c)

a is applied to the left and a = gsin θ

(d)

a is applied to the left and a = gcos θ

A wind-powered generator converts wind energy into electric energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to

(a)

v

(b)

v²

(c)

v³

(d)

v⁴

From a disc of radius R a mass M, a circular hole of diameter R, whose rim passes through the center is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis passing through it

(a)

15MR²/32

(b)

13MR²/32

(c)

11MR²/32

(d)

9MR²/32

The work done by the Sun’s gravitational force on the Earth is

(a)

always zero

(b)

always positive

(c)

can be positive or negative

(d)

always negative

A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

(a)

energy = 4 V T \(\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right) \)is released

(b)

energy = 3 V T \(\left( \frac { 1 }{ r } +\frac { 1 }{ R } \right) \)is absorbed

(c)

energy = 3 V T \(\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right) \)is released

(d)

energy is neither released nor absorbed