(a) 4o C (b) 25o C (c) 50o C (d) 75o C Ans. d (8)
(a) 2 : 3 (b) 3 : 4 (c) 3 : 2 (d) 6 : 1 Answer-b (10)
(a) Horizontal (b) Almost vertical (c) Concave (d) Convex Ans. d (4)
(a) Energy density =(1/2)×strain×stress (b) Energy density =(strain) 2 × volume (c) Energy density = (strain)× volume (d) Energy density = (stress)× volume Answer-a (14)
The maximum force, in addition to the weight required to pull a wire of 5.0 cm long from the surface of water at temperature 20oC, is 728 dynes. The surface tension of water is (a) 7.28 N/cm (b) 7.28 dyne/cm …
(a) Increased kinetic energy (b) Increased potential energy (c) Decreased kinetic energy (d) Decreased potential energy Answer-b (13)
(a) 75 joule (b) 60 joule (c) 50 joule (d) 100 joule Answer-a (6)
25. The work per unit volume to stretch the length by 1% of a wire with cross sectional area of 1 mm2 will be (Y=9×1011 N/m2) (a) 9×1011 J …
(a) Increase (b) Decrease (c) Remain unchanged (d) None of the above Ans. a (40)
24.A wire of length 50 cm and cross sectional area of 1 sq. mm is extended by 1 mm. The required work will be(Y=2×1010 N/m2) (a) 6×10-6 J …
(a) Attraction (b) Repulsion (c) Attraction or repulsion (d) None of the above Ans. a (2)
20.K is the force constant of a spring. The work done in increasing its extension from l1 to l2 will be (a) k(l2 – l1 ) …
(a) Cohesive force of oil>> adhesive force between oil and glass (b) Cohesive force of oil > cohesive force of water (c) Oil repels water (d) Cohesive force for water > adhesive force between water and oil molecules Ans. d …
(a) 2 TL (b) 4 TL (c) 8 TL (d) 10 TL Ans. (c) Force on each side =2TL (due to two surfaces) Force on the frame = 4(2TL)=8TL (8)
19.When a force is applied on a wire of uniform cross-sectional area 3×10-6 m2 and length 4m, the increase in length is 1 mm. Energy stored in it will be (Y=2×1011 N/m2) (a) 6250 J (b) 0.177 J (c) 0.075 …
(a) Increases with area (b) Decreases with area (c) Increase with temperature (d) Decrease with temperature Ans. d (7)
(a) Solids, liquids and gases (b) Liquids (c) Gases (d) Matter Ans. b (6)
(a) 30 dynes (b) 60 dynes (c) 750 dynes (d) 750 π dynes Ans. d (38)
(a) Y×(Strain2/Volume) (b) Stress × Strain × Volume (c) (Stress2×Volume) / (2Y) (d) (1/Y) × Stress × Strain × Volume Answer-c (12)
(a) Only on the cohesive force of liquid molecules (b) Only on the adhesive force between the molecules of glass and liquid (c) Only on relative cohesive and adhesive force between the atoms (d) Neither on cohesive nor on adhesive …
(a) Dancing of a camphor piece over the surface of water (b) Small mercury drop itself becomes spherical (c) A liquid surface comes at rest after stirring (d) Mercury does not wet the glass vessel Ans. c (6)
(a) (YxA)/(2L) (b) (Yx2 A)/(L) (c) (Yx2 A)/(2L) …
(a) C.F. for water > A.F. for water and oil (b) C.F. for oil > A.F. for water and oil (c) C.F. for oil < A.F. for water and oil (d) None of the above Ans. a (31)
21. When a 4 kg mass is hung vertically on a light spring that obeys Hooke’s law, the spring stretches by 2 cms. The work required to be done by an external agent in stretching this spring by 5 cms …
(a) Force of attraction between hair (b) Surface tension (c) Viscosity of water (d) Characteristic property of hairs Ans. b (8)
(a) water is absorbed by the coating (b) Cohesive force becomes greater (c) Water is not scattered away by the coating (d) Angle of contact decreases Ans. b (15)
(a) Surface tension (b) Less weight (c) Upthrust of liquid (d) None of the above Ans. a (12)
(a) Fl/2AL (b) FA/2L (c) FL/2A …
(a) Force of surface tension is equal and opposite to the force of gravity (b) Force of surface tension predominates the force of gravity (c) Force of gravity predominates the force of surface tension (d) Force of gravity and force …
(a) Elastic membrane is formed on water due to property of surface tension (b) Spiders and insects are lighter (c) Spiders and insects swim on water (d) Spider and insects experience upthrust Ans. (a) Weight of spiders or insects can be …
(a) Increase in the saturated vapour pressure of water (b) Root mean square velocity of air molecules inside the bubble increases (c) Decrease in surface tension of water (d) All of the above Ans. d (10)
(a) 0°C (b) 277 K (c) 370°C (d) Slightly less than 647 K Ans. c,d (11)
(a) It will remain on it as a sphere (b) It will spread as a thin layer (c) It will be partly as spherical droplets and partly as thin film (d) It will float as a distorted drop on the …
(a) Increases (b) Decreases (c) Remains the same (d) Increases then decreases Ans. b (12)
(a) Chemicals of soap change (b) It increases the surface tension of the solution (c) It absorbs the dirt (d) It lowers the surface tension of the solution Ans. (d) Soap helps to lower the surface tension of solution, thus …
(a) Frictional forces between molecules (b) Cohesive forces between molecules (c) Adhesive forces between molecules (d) Gravitational forces Ans. b (15)
(a) Density of the liquid (b) Surface tension (c) Atmospheric pressure (d) Gravity Ans. b (12)
(a) Zero (b) Infinite (c) Between 0 and ∞ (d) Can not be determined Ans. a (13)