**Q1** **The lower surface of a cube is fixed. On its upper surface, force is applied at an angle of 300 from its surface. the change will be in its.**

a) Shape

b) Size

c) Volume

d) Both shape and size

**Q2** **If the density of the material increase, the value of Young’s modulus.**

a) Increases

b) decreases

c) first increases, then decreases

d) first decreases, then increases

**Q3** **For a given material, the Young’s modulus is 2.4 times that of rigidity modulus. Its Poisson’s ratio is.**

a) 2.4

b) 1.2

c) 0.4

d) 0.2

**Q4** **Poisson’s ratio cannot have the value.**

a) 0.1

b) 0.7

c) 0.2

d) 0.5

**Q5** **If the density of a block is 981 kg/m3 then it shall.**

a) Sink in water

b) Float with some part immersed in water

c) Float completely immersed in water

d) Float completely out of water.

**Q6** **A piece of ice is floating in a jar containing water. When the ice melts, then the level of water:-**

a) Rises

b) Falls

c) Remains unchanged

d) Changes erratically

**Q7** **Torr’ is the unit of :-**

a) Pressure

b) Density

c) Volume

d) Flux

**Q8** **Which of the following works on Pascal’s law?**

a) Sprayer

b) Venturimeter

c) Hydraulic lift

d) Aneroid barometer

**Q9** **A body measures 5 N in air and 2 N when put in water. The buoyant force is.**

a) 7 N

b) 9 N

c) 3 N

d) None of these

**Q10** **Hydraulic press is bases upon.**

a) Archimede’s principle

b) Bernoulli’s theorem

c) Pascal’s law

d) Reynold’s number

**Q11** **A wooden block is taken to the bottom of a lake of water and then released. It rise up with a.**

a) Constant acceleration

b) Decreasing acceleration

c) Constant velocity

d) Decreasing velocity

**Q12** **Assertion:- Gases also behave as fluids.**

** Reason:- Gas molecules are bounded by cohesive forces.**

a) A

b) B

c) C

d) D

**Q13** **Scent sprayer is based on.**

a) Charle’s law

b) Archimede’s princip

c) Boyle’s law

d) Bernoulli’s theorem

**Q14** **Bernoulli’s equation for steady, non-viscous, incompressible flow expresses the.**

a) Conservation of angular momentum

b) Conservation of density

c) Conservation of momentum

d) Conservation of mechanical energy.

**Q15** **Application of Bernoulli’s theorem can be seen in.**

a) Dynamic lift to aeroplane

b) Hydraulic press

c) Speed boat

d) None of these

**Q16** **The velocity of falling rain drop attain limited value because of.**

a) Surface tension

b) upthrust due to air

c) viscous force exerted by air

d) air current

**Q17** **Poise is the unit of.**

a) Pressure

b) Friction

c) Surface tension

d) Viscosity

**Q18** **Two rain drops falling through air have radii in the ratio 1 : 2. They will have terminal velocity in the ratio.**

a) 4 : 1

b) 1 : 4

c) 2 : 1

d) 1 : 2

**Q19** **A sphere of mass M and radius R is falling in a viscous fluid. The terminal velocity attained by the falling object will be proportional to.**

a) MR to the power (2)

b) M/R

c) MR

d) M/R to the power (2)

**Q20** **Spiders and insects move and run about on the surface of water without sinking because:-**

a) Elastic membrane is formed on water due to propery of surface tension

b) Spiders and insects are lighter

c) Spiders and insects swim on water

d) Spiders and insects experience up-thrust

**Q21** **A water drop is divided into 8 equal droplets. The pressure difference between inner and outer sides of the big drop.**

a) will be the same as for smaller droplet

b) will be half of that for smaller droplet

c) will be one-forth of that for smaller droplet

d) will be twice of that for smaller drople

**Q22** **Shape of meniscus for a liquid of zero angle of contact:-**

a) plane

b) parabolic

c) hemi-spherical

d) cylindrical

**Q23** **Due to capillary action a liquid will rise in a tube if angle of contact is.**

a) acute

b) obtuse

c) 90 degree

d) 180 degree

**Q24** **Two droplets merge with each other and form a large droplet. In this process:-**

a) Energy is liberated

b) Energy is absorbed

c) Neither liberated nor absorbed

d) Some mass is converted into energy

**Q25** **If the surface tension of a liquid is T and its surface area is increased by A, then the surface energy of that surface will be increased by:-**

a) AT

b) A/T

c) A to the power (2)T

d) A to the power (2) T to the power (2)

**Q26** **The excess of pressure inside a soap bubble than that of the outer pressure is :-**

a) 2T/r

b) 4T/r

c) T/2r

d) T/r

**Q27** **At which angle liquid will not wet solid.**

a) zero

b) acute

c) 45 degree

d) obtuse

**Q28** **Adding detergents to water helps in removing dirty greasy stains. This is because:-**

** **

**(a) It increases the oil-water surface tension**

** **

**(b) It decreases the oil-water surface tension**

** **

**(c) It increases the viscosity of the solution **

** **

**(d) Dirt is held suspended surrounded by detergent molecules**

a) (b) and (d)

b) (a) only

c) (c) and (d)

d) only

**Q29** **The excess pressure inside a soap bubble A is twice that in another soap bubble B. The ratio of volumes of A and B is:-**

a) 1 : 2

b) 1 : 4

c) 1 : 8

d) 1 : 16

**Q30** **The wettability of a surface by a liquid depends primarily on :-**

a) angle of contact between the surface and the liquid

b) viscosity

c) surface tension

d) density

**Q31** **Water rises to height ‘h’ in capillary tube. If the length of capillary tube above the surface of water is made less than ‘h’, then:-**

a) water does not rise at all.

b) water rises upto the tip of capillary tube and the starts overflowing like a fountain.

c) water rises upto the top of capillary tube and stays there without overflowing.

d) water rises upto a point a little below the top and stays there.

**Q32** **Assertion :- Work is required to be done to stretch a wire. This work is stored in the wire in the form of elastic potential energy.**

**Reason :- Work is required to be done against the intermolecular forces of attraction.**

a) A

b) B

c) C

d) D

**Q33** **Assertion:- The bridges are declared unsafe after a long use.**

**Reason:- Elastic strength of bridges losses with time.**

a) A

b) B

c) C

d) D

**Q34** **Assertion:- Young’s modulus for a perfectly plastic body is zero.**

**Reason :- For a perfectly plastic body, restoring force is zero.**

a) A

b) B

c) C

d) D

**Q35** **Assertion:- Identical springs of steel and copper are equally stretched. More work will be done on the steel spring.**

**Reason:- Steel is more elastic than copper**

a) A

b) B

c) C

d) D

**Q36** **Assertion:- Stress is the internal force per unit area of a body**

**Reason :- Rubber is more elastic than steel**

a) A

b) B

c) C

d) D

**Q37** **Assertion:- Rubber is more elastic than glass.**

**Reason :-The rubber has higher modulus of elasticity than glass**

a) A

b) B

c) C

d) D

**Q38** **Assertion:- Specific gravity of a fluid is a dimensionless quantity.**

**Reason:- It is the ratio of density of fluid to the density of water.**

a) A

b) B

c) C

d) D

**Q39** **Assertion:-The size of a hydrogen balloon increase as it rise in air.**

**Reason:- The material of the balloon can be easily stretched.**

a) A

b) B

c) C

d) D

**Q40** **Assertion:- Machine parts are jammed in winter.**

**Reason:-The viscosity of lubricant used in machine part decrease at low temperature.**

a) A

b) B

c) C

d) D

**ANSWERS **

**1) d**

**2) a**

**3) d**

**4) b**

**5) b**

**6) c**

**7) a**

**8) c**

**9) c**

**10) c**

**11) a**

**12) c**

**13) d**

**14) d**

**15) a**

**16) c**

**17) d**

**18) b**

**19) b**

**20) a**

**21) b**

**22) c**

**23) a**

**24) a**

**25) a**

**26) b**

**27) d**

**28) a**

**29) c**

**30) a**

**31) c**

**32) a**

**33) a**

**34) a**

**35) a**

**36) c**

**37) d**

**38) a**

**39) b**

**40) c**