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Which one of the following is a major factor for deforestation in India?

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Important Questions on Laws of Motion

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

Two spherical black bodies have radii

r_{1}

and

r_{2}

. Their surface temperatures are

T_{1}

and

T_{2}

. If they radiate same power then

\frac{r_{2}}{r_{1}}

MEDIUM

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A mass

M

attached to a horizontal spring executes

S . H . M .

of amplitude

A_{1}

. When the mass

M

passes through its mean position, then a smaller mass

m

is placed over it and both of them move together with amplitude

A_{2}

. The ratio of

(\frac{A_{1}}{A_{2}})

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A copper rod of

88 c m

and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is

(α_{C u} = 1.7 \times 10^{- 5} K^{- 1} a n d α_{Al} = 2.2 \times 10^{- 5} K^{- 1})

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A body of mass

M

moving with velocity

v

explodes into two equal parts. If one part comes to rest and the other part moves with velocity

v_{0}

; what would be the value of

v_{0}

MEDIUM

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A rod, of length

L

at room temperature and uniform area of cross section

A,

is made of a metal having coefficient of linear expansion

α / ° C

It is observed that an external compressive force

F

is applied on each of its ends, prevents any change in the length of the rod when its temperature rises by

∆ T K

Young's modulus,

Y

for this metal is:

MEDIUM

Physics>Mechanics>Laws of Motion>Conservation of Momentum

An ideal gas is expanding such that

P T =

constant. The coefficient of volume expansion of the gas is

MEDIUM

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A block of mass

10 kg

is kept on a rough inclined plane as shown in the figure. A force of

3 N

is applied on the block. The coefficient of static friction between the plane and the block is

0.6 .

What should be the minimum value of force

P,

such that the block does not move downward? (take

g = 10 m s^{- 2}

)

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

An ideal black body, at room temperature, is thrown into a furnance. It is observed that,

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A metal ball of surface area

200 {cm}^{2}

and temperature

527^{0} C

is surrounded by a vessel at

27^{0} C

. If the emissivity of the metal is 0.4, then the rate of loss of heat from the ball is

(σ = 5.67 \times 1 0^{- 8} J / m^{2} - s - k^{4})

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A black body radiates energy at the rate of

E W m^{- 2}

at a high temperature

T K

. When the temperature is reduced to

(\frac{T}{2})

K, the radiant energy is

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

In which mode of transmission, the heat waves travel along straight line with the speed of light?

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A perfect black body is one whose emissive power is

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

Two spheres of the same material have radii

1 m

and

4 m

and temperature

4000 K

and

2000 K

respectively. The ratio of the energy radiated per second by the first sphere to that by the second is

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

The temperature at which a black body ceases to radiate energy, is

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

Following graphs show the variation in the intensity of heat radiations by the black body and frequency at a fixed temperature. Choose the correct option.

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

We consider the radiation emitted by the human body. Which of the following statements is true?

HARD

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A spherical black body with a radius of

12 cm

radiates

450 W

power at

500 K

. If the radius were halved, and the temperature doubled, the power radiated in

watt

would be

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

A black body is heated from

27 ° C

927 ° C

. The ratio of radiation emitted will be,

EASY

Physics>Mechanics>Laws of Motion>Conservation of Momentum

Two spheres made of same material have radii in the ratio

2 : 1

. If both the spheres are at same temperature, then what is the ration of heat radiation energy emitted per second by them?

Which one of the following is a major factor for deforestation in India?

Important Questions on Laws of Motion

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