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A solid object having uniform density $(ρ)$ and varying cross-sectional area (which is circular) is placed on smooth horizontal surface as shown. Then the value of $\frac{R_{1}}{R_{2}}$ if the stress throughout its height remains same and having value equal to $c$ .

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Important Questions on Physics

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General Awareness>General Science>Physics>Properties of Matter

A submarine experiences a pressure of

5.05 \times 10^{6} P a

at a depth of

d_{1}

in a sea. When it goes further to a depth of

d_{2}

, it experiences a pressure of

8.08 \times 10^{6} P a

. Then

d_{2} - d_{1}

is approximately (density of water

= 10^{3} k g / m^{3}

and acceleration due to gravity

= 10 m s^{- 2}

MEDIUM

General Awareness>General Science>Physics>Properties of Matter

Consider a water jar of radius R that has water filled up to height H and is kept on a stand of height h (see figure). Through a hole of radius r

(r < < R)

at its bottom, the water leaks out and the stream of water coming down towards the ground has a shape like a funnel as shown in the figure. If the radius of the cross-section of water stream when it hits the ground is x. Then:

EASY

General Awareness>General Science>Physics>Properties of Matter

A steel wire having a radius of

2.0 m m

, carrying a load of

4 k g,

is hanging from a ceiling. Given that

g = 3.1 π m s^{- 2},

what will be the tensile stress that would be developed in the wire?

MEDIUM

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Speed of a transverse wave on a straight wire (mass

6.0 g,

length

60 c m

and area of cross-section

1.0 m m^{2}

90 {m s}^{- 1}

. If the Young's modulus of wire is

16 \times 10^{11} N m^{- 2}

, the extension of wire over its natural length is:

MEDIUM

General Awareness>General Science>Physics>Properties of Matter

The following observations were taken for determining surface tension

T

of water by capillary method:

diameter of capillary,

D = 1.25 \times 10^{- 2} m

rise of water,

h = 1.45 \times 10^{- 2} m

Using

g = 9.80 m s^{- 2}

and the simplified relation

T = \frac{r h g}{2} \times 10^{3} N m^{- 1}

the possible error in surface tension is closest to:

EASY

General Awareness>General Science>Physics>Properties of Matter

Which one of the following statement is correct?

HARD

General Awareness>General Science>Physics>Properties of Matter

0.27 g

of a long chain fatty acid was dissolved in

100 {c m}^{3}

of hexane.

10 m L

of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is formed. The distance from edge to centre of the watch glass is

10 c m

. What is the height of the monolayer?
[Density of fatty acid

= 0.9 g c m^{- 3}; π = 3]

EASY

General Awareness>General Science>Physics>Properties of Matter

A metallic rod breaks when strain produced is

0.2 %

. Young's modulus of the material of the rod is

7 \times 10^{9} N m^{- 2}

. What should be its area of cross-section to support a load of

10^{4} N

EASY

General Awareness>General Science>Physics>Properties of Matter

A man grows into a giant such that his linear dimensions increase by a factor of

9 .

Assuming that his density remains same, the stress in the leg will change by a factor of:

EASY

General Awareness>General Science>Physics>Properties of Matter

When one end of the capillary is dipped in water, the height of the water column is

h

. The upward force of

105 dyne

due to surface tension is balanced by the force due to the weight of the water column. The inner circumference of the capillary is
(Surface tension of water

= 7 \times 10^{- 2} N m^{- 1})

HARD

General Awareness>General Science>Physics>Properties of Matter

Consider a solid sphere of radius

R

and mass density

ρ (r) = ρ_{0} (1 - \frac{r^{2}}{R^{2}}), 0 < r \leq R .

The minimum density of a liquid in which it will float is:

MEDIUM

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A particle of mass

1 kg

is moving in SHM with a path length of

0.01 m

and frequency of

50 Hz

. The maximum force in newton, acting on the particle is

MEDIUM

General Awareness>General Science>Physics>Properties of Matter

A small spherical droplet of density

d

is floating exactly half immersed in a liquid of density

ρ

and surface tension

T .

The radius of the droplet is (take note that the surface tension applies an upward force on the droplet):

MEDIUM

General Awareness>General Science>Physics>Properties of Matter

In an experiment, brass and steel wires of length

1 m

each with areas of cross section

1 m m^{2}

are used. The wires are connected in series and one end of the combined wire is connected to a rigid support and other end is subjected to elongation. The stress required to produce a net elongation of

0.2 m m

is,
[Given, the Young's Modulus for steel and brass are, respectively,

120 \times 10^{9} N / m^{2}

and

60 \times 10^{9} N / m^{2}

]

EASY

General Awareness>General Science>Physics>Properties of Matter

An aluminium sphere is dipped into water. Which of the following is true?

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General Awareness>General Science>Physics>Properties of Matter

A

and

B

are two wires. The radius of

A

is twice that of

B

. They are stretched by the same load. Then the stress on

B

MEDIUM

General Awareness>General Science>Physics>Properties of Matter

A fluid is flowing through a horizontal pipe of varying cross-section, with

v {ms}^{- 1}

at a point where the pressure is

P

Pascal. At another point where pressure

\frac{P}{2}

Pascal its speed is

V {ms}^{- 1}

. If the density of the fluid is

ρ kg - m^{- 3}

and the flow is streamline, then

V

is equal to

EASY

General Awareness>General Science>Physics>Properties of Matter

One end of a horizontal thick copper wire of length

2 L

and radius

2 R

is welded to an end of another horizontal thin copper wire of length

L

and radius

R

. When the arrangement stretched by applying forces at two ends, the ratio of the elongation in the thin wire to that in the thick wire is

EASY

General Awareness>General Science>Physics>Properties of Matter

A rectangular film of liquid is extended from

(4 cm \times 2 cm)

(5 cm \times 4 cm)

. If the work done is

3 \times 10^{- 4} J

, the value of the surface tension of the liquid is

HARD

General Awareness>General Science>Physics>Properties of Matter

Assume that a drop of a liquid evaporates by a decrease in its surface energy so that its temperature remains unchanged. The minimum radius of the drop for this to be possible is. (The surface tension is

T

, the density of the liquid is

ρ

and

L

is its latent heat of vaporisation.)

A solid object having uniform density ρ and varying cross-sectional area (which is circular) is placed on smooth horizontal surface as shown. Then the value of R1R2 if the stress throughout its height remains same and having value equal to c.

Important Questions on Physics

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A solid object having uniform density $(ρ)$ and varying cross-sectional area (which is circular) is placed on smooth horizontal surface as shown. Then the value of $\frac{R_{1}}{R_{2}}$ if the stress throughout its height remains same and having value equal to $c$ .