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If a bullet is fired from a gun. Then

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Important Questions on Physical World

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Physics>Mechanics>Physical World>Nature of Physical Laws

Match the columns I and II

	Column I		Column II
A	Stoke's law	I	Pressure and energy
B	Turbulence	II	Hydraulic lift
C	Bernoulli's Principle	III	Viscous drag
D	Pascal's law	IV	Reynold's number

The correct match is

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Physics>Mechanics>Physical World>Nature of Physical Laws

Which of the following statement is incorrect?

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Physics>Mechanics>Physical World>Nature of Physical Laws

The ratio

(\frac{E}{W})

of relative strength of electromagnetic force

(E)

to weak nuclear force

(W)

is,

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Physics>Mechanics>Physical World>Nature of Physical Laws

Which of the following interactions is the weakest?

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Physics>Mechanics>Physical World>Nature of Physical Laws

A train is moving slowly at

2 m / s

next to a railway platform. A man,

1.5 m

tall, alights from the train such that his feet are fixed on the ground. Taking him to be a rigid body, the instantaneous angular velocity (in

rad / s

) is

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Physics>Mechanics>Physical World>Nature of Physical Laws

Choose the correct statement from following.

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Physics>Mechanics>Physical World>Nature of Physical Laws

Which of the following is a possible final step in applying the scientific method?

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Physics>Mechanics>Physical World>Nature of Physical Laws

A particle is moving uniformly along a straight line as shown in the figure. During the motion of the particle from $A$ to $B$ , the angular momentum of the particle about ${}^{'}O^{'}$

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Physics>Mechanics>Physical World>Nature of Physical Laws

A shell of mass

20 g

is fired by a gun of mass

100 kg .

If the shell leaves the gun with a speed of

800 m / s,

the speed of recoil of the gun is

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Physics>Mechanics>Physical World>Nature of Physical Laws

The maximum and minimum distances of a comet from the sun are

1.4 \times 10^{12} m

and

7 \times 10^{10}

m .

If it's velocity nearest to the sun is

6 \times 10^{14} m / s,

what is its velocity in the farthest position? (Assume the comet to be spherical)

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Physics>Mechanics>Physical World>Nature of Physical Laws

A gas molecule of mass

M

at the surface of the earth has kinetic energy equivalent to

0 ° C

. If it were to go up straight without colliding with any other molecules, how high would it rise? Assume that the height attained is much less than the radius of the earth. (

k_{B}

is Boltzmann constant)

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Physics>Mechanics>Physical World>Nature of Physical Laws

Let

G, W, S

and

E

be relative strengths of gravitational, weak nuclear, strong nuclear and electromagnetic forces. Identify the correct option

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Physics>Mechanics>Physical World>Nature of Physical Laws

Three point masses each of mass

m

are kept at the corners of an equilateral triangle of side

L

. The system rotates about the center of the triangle without any change in the separation of masses during rotation. The period of rotation is directly proportional to

(\cos 30 ° = s i n 60 ° = \frac{\sqrt{3}}{2})

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Physics>Mechanics>Physical World>Nature of Physical Laws

(A) Ratio of the relative strength of gravitational to weak force is nearly $10^{- 3}$
(B) Ratio of the relative strength of gravitational to weak force is less than $10^{- 3}$
(C) Ratio of the relative strength of strong nuclear to electromagnetic force is nearly $10^{2}$
(D) Ratio of the relative strength of strong nuclear to electromagnetic force is nearly $10^{- 2}$ .

Which of the following is true?

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Physics>Mechanics>Physical World>Nature of Physical Laws

A uniformly thick wheel with moment of inertia

I

and radius

R

is free to rotate about its centre of mass (see fig). A massless string is wrapped over its rim and two blocks of masses

m_{1}

and

m_{2} (m_{1} > m_{2})

are attached to the ends of the string. The system is released from rest. The angular speed of the wheel when

m_{1}

descends by a distance

h

is:

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Physics>Mechanics>Physical World>Nature of Physical Laws

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1m 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? Fat supplies

3.8 \times 10^{7}

J of energy per kg which is converted to mechanical energy with a 20% efficiency rate. Take

g = 9.8 m s^{- 2}

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Physics>Mechanics>Physical World>Nature of Physical Laws

For a simple pendulum, a graph is plotted between its kinetic energy (K.E.) and potential energy (P.E.) against its displacement d. which one of the following represents these correctly? (graphs are schematic and not drawn to scale)

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Physics>Mechanics>Physical World>Nature of Physical Laws

Which of the following forces have highest range?
(a) Gravitational force
(b) Weak Nuclear force
(c) Electromagnetic force
(d) Strong Nuclear force

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Physics>Mechanics>Physical World>Nature of Physical Laws

In a particle accelerator, a current of

500 μ A

is carried by a proton beam in which each proton has a speed of

3 \times 10^{7} m / s

. The cross-sectional area of the beam is

1.50 m m^{2} .

The charge density in this beam (in

C / m^{3})

is close to

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Physics>Mechanics>Physical World>Nature of Physical Laws

Which of the following represents fundamental forces of nature?

If a bullet is fired from a gun. Then

Important Questions on Physical World

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