Physics - Properties of Matter
Exam Duration: 45 Mins Total Questions : 30
A bolloon floating in air is given a slight lateral horizontal displacement. The baloon shall now be
- (a)
in stable equilibrium
- (b)
in unstable equilibrium
- (c)
in neutral equilibrium
- (d)
oscillating
Young's modulus is defined as ratio of normal stress to longitudinal strain. Hence the term 'force' refers to
- (a)
external applied force
- (b)
deforming force
- (c)
restoring force
- (d)
breaking force
Choose correct statement :
- (a)
Metals have high young modulus and low elastic strain
- (b)
Glass has young modulus and low elastic strain
- (c)
Plastics are less stiff and do not obey Hooke's law like metals do
- (d)
All of the above
Choose correct statement :
- (a)
carbon atoms in the form of diamond offer a very large value of Young modulus
- (b)
Carbon atoms in the form of graphite offer a small value of young modulus
- (c)
Carbon atoms always offer constant value of Young modulus
- (d)
Both (a) and (b) are correct.
A ship,floating in clear water of density 1000 kg m-3 moves to sea-water of density1050 kg m-3 where it floats again.The upthrust on the ship then
- (a)
increases by 0.05 times
- (b)
decreases by 0.05 times
- (c)
stays constant
- (d)
first increases and then stays constant
Consider the following statements :
A.The condition for a body to float in stable equilibrium is when its centre of gravity is below the centre of buoyancy.
B.A floating body is given an angular displacement in a clockwise direction.It comes back to its original position if the body is in neutral equilibrium.
C.A cylinder floating in water is an example of unstable equilibrium.
- (a)
if A is correct only
- (b)
if A,B are correct only
- (c)
if A,B,C are correct
- (d)
if B,C are correct only
The terminal velocity of a sphere following freely through a viscous fluid is directly proportional to
- (a)
size of the sphere
- (b)
surface area of the sphere
- (c)
surface volume of the sphere
- (d)
coefficient of viscosity of the fluid
At N.T.P., the rms speed of hydrogen molecules is 1,840 ms-1.The rms speed of oxygen molecules at NTP will be
- (a)
230 ms-1
- (b)
460 ms-1
- (c)
3680 ms-1
- (d)
7360 ms-1
When the temperature of a perfect gas increases
- (a)
the intermolecular attraction decreases
- (b)
the intermolecular attraction remains constant
- (c)
the intermolecular attraction is zero
- (d)
the molecules move far apart
At 27°C and 1.0 x 105 Pa pressure,air has a density of 0.09 kg m-3.At 27°C and 2.0 x 105 Pa pressure,the air density in kg m-3 is
- (a)
0.45
- (b)
0.40
- (c)
0.35
- (d)
0.18
An object is floating in a beaker of water.If taken from one place to another where the acceleration of gravity g is substantially different,the depth of submersion of the floating object
- (a)
will remain the same
- (b)
will decreases if g decreases
- (c)
will increases if g decreases
- (d)
depends on the density of the object
The compressibility is minimum for
- (a)
water
- (b)
glycerine
- (c)
mercury
- (d)
ether
A material has Poisson's ratio 0.5.If a rod of the material has a longitudinal strain 2 x 10-3,the percentage change in volume is
- (a)
0.6
- (b)
0.4
- (c)
0.2
- (d)
zero
A ball falling in a lake of depth 200 m shows a decrease of 0.1% in its volume at the bottom.What is the bulk modules?
- (a)
19.6 x 108 Nm-2
- (b)
19.6 x 10-10 Nm-2
- (c)
19.6 x 1010 Nm-2
- (d)
19.6 x 10-8 Nm-2
A wire of length L and radius r is rigidly fixed at one end.On stretching the other end of the wire with a force F, the increase in its length is l.If another wire of same material but of length 2L and radius 2r is stretched with a force 2F, the increase in its length will be
- (a)
l/4
- (b)
l/2
- (c)
l
- (d)
2l
A stretched rubber has
- (a)
increased potential energy
- (b)
increased kinetic energy
- (c)
decreased kinetic energy
- (d)
decreased kinetic energy
Two bodies are in equillibrium when suspended in water from the arms of a balance.The mass of one is 36 g and its density is 9 g/c.c.If the mass of the other is 48 g,its density will be(in g/cm3)
- (a)
4/3
- (b)
3/2
- (c)
3
- (d)
5
A boat having length 3m and breadth 2 m is floating on a lake.The boat sinks by 1 cm when a man gets on it.The mass of the man is
- (a)
60 kg
- (b)
72 kg
- (c)
128 kg
- (d)
90 kg
A piece of brass (Cu + Zn) weights 12.9 g in air.When completely immersed in water it weights 11.3 g.What is the mass of 'Cu' in the alloy?(Relative density of Cu and Zn are 8.9 and 7.1 respectively)
- (a)
7.61 g
- (b)
5.61 g
- (c)
8.61 g
- (d)
10.61 g
A tank 4 m long,3 m broad and 1 m deep is filled with water.The thrust on one of the sides is 1.96 x 104 N.The point of action of this resultant thrust lies at a distance y from the surface of water such that y is
- (a)
3/4 m
- (b)
3/8 m
- (c)
2/3 m
- (d)
4/5 m
The rain drops are in spherical shape due to
- (a)
viscosity
- (b)
surface tension
- (c)
thrust on drop
- (d)
residual pressure
The r.m.s speed of O2 molecules at temperature T is \(\vartheta\).If the temperature is doubled and oxygen gas is dissociated into atomic oxygen the r.m.s speed is
- (a)
\(\vartheta\)
- (b)
2\(\vartheta\)
- (c)
\(\frac{3}{2}??\vartheta\)
- (d)
\(\frac{\vartheta}{2}\)
If Cs be the velocity sound in air and C be the r.m.s. speed,then
- (a)
Cs < C
- (b)
Cs = C
- (c)
\(C_s = C \times\ \sqrt\frac{\gamma}{3}\)
- (d)
None of these
22 g of CO2 at 27°C is mixed with 16 g of O2 at 37°C.The temperature of mixture is
- (a)
27°C
- (b)
30.5°C
- (c)
32°C
- (d)
37°C
Air is filled at 60°C in a vessel of open mouth.The vessel is heated to a temperature T so that one-fourth part of air escapes.Assuming the volume of the vessel remaining constant, the value of T is
- (a)
80°C
- (b)
143°C
- (c)
333°C
- (d)
416°C
When two soap bubbles of radii r1 and r2 (r2 > r1) coalesce,the radius of curvature of common surface is
- (a)
(r2 - r1)
- (b)
(r2 + r1)
- (c)
(r2 - r1)/r1r2
- (d)
r1r2/(r2 - r1)