(a) Magnetic substances (b) Molecules of different substances (c) Molecules of same substances (d) None of these Ans. (c) The cohesive force is the force of attraction between the molecules of same substance (15)
(a) Surface tension of water is very high (b) Surface tension of water is very low (c) Viscosity of oil is high (d) Viscosity of water is high Ans. a (59)
The force required to separate two glass plates of area 10-2m2 with a film of water 0.05 mm thick between them, is (Surface tension of water is 70 x 10-3 N/m) (a) 28 N (b) 14 N (c) 50 N …
(a) Viscosity (b) Surface tension (c) Weight (d) Floating force Ans. b (12)
(a) Surface tension is more (b) Surface tension is less (c) Consumes less soap (d) None of these Ans. (b) Surface tension of water decrease with rise in temperature. (9)
A 10 cm long wire is placed horizontally on the surface of water and is gently pulled up with a force of 2 ×10-2 N to keep the wire in equilibrium. The surface tension, in Nm-1, of water is (a) …
(a) 2πrT + W (b) 2πrT COSθ – W (c) 2πrT COSθ +W (d) W-2πrT COSθ Ans. c (11)
(a) Atmospheric pressure exerts a force on a liquid drop (b) Volume of a spherical drop is minimum (c) Gravitational force acts upon the drop (d) Liquid tends to have the minimum surface area due to surface tension Ans. (d) …
(a) Inertia (b) Pressure (c) Surface tension (d) Viscosity Ans. (c) Surface tension pulls the plates towards each other. (6)
(a) Cohesive force is less than adhesive force (b) Cohesive force is greater than adhesive force (c) Angle of contact is less than 90o (d) Cohesive force is equal to adhesive force Ans. b (28)
(a) It will mix up with oil (b) It spreads in the form of a film (c) It will deform (d) It remains spherical Ans. d (11)
(a) It increases with the increase of temperature (b) Nature of the liquid in contact (c) Presence of soap that increases it (d) Its variation with the concentration of the liquid Ans. d (12)
(a) Angle of contact is acute (b) Cohesion force is more (c) Adhesion force is more (d) Density of mercury is more Ans. b (11)
(a) 4o C (b) 25o C (c) 50o C (d) 75o C Ans. d (8)
(a) Horizontal (b) Almost vertical (c) Concave (d) Convex Ans. d (4)
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) Increase (b) Decrease (c) Remain unchanged (d) None of the above Ans. a (40)
(a) Attraction (b) Repulsion (c) Attraction or repulsion (d) None of the above Ans. a (2)
(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)
(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 (39)
(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) 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)
(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) 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 (14)
(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) Surface tension of the liquid (b) Density of liquid (c) Viscosity of liquid (d) Temperature of air only Ans. d (102)
(a) Surface tension of the liquid (b) Density of liquid (c) Viscosity of liquid (d) Temperature of air only Ans. a (63)
(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)