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## Sunday 21 February 2021

### CBSE Class 11 Physics - MCQ and Online Tests - Unit 10 - Mechanical Properties of Fluids

#### CBSE Class 11 Physics – MCQ and Online Tests – Unit 10 – Mechanical Properties of Fluids

Every year CBSE schools conducts Annual Assessment exams for 6,7,8,9,11th standards. These exams are very competitive to all the students. So our website provides online tests for all the 6,7,8,9,11th standard’s subjects. These tests are also very effective and useful for those who preparing for any competitive exams like Olympiad etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE syllabus. While attempting these our students can identify the weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly.

#### CBSE Class 11 Physics – MCQ and Online Tests – Unit 10 – Mechanical Properties of Fluids

Question 1.
Pressure inside two soap bubbles is 1.01 and 1.02 atmospheres. ratio between their volume is
(a) 102 : 101
(b) (102)3 : (101)3
(c) 8 : 1
(d) 2 : 1

Question 2.
One end of a towel dips into a bucket full of water and other end hangs over the bucket. It is found that after some time the towel becomes fully wet. It happens
(a) Because viscosity of eater is high
(b) Because of the capillary action of cotton threads
(c) Because of gravitational force
(d) Because of evaporation of water.

Question 3.
Plants get water through the roots because of
(a) Capillarity
(b) Viscosity
(c) Gravity
(d) Elasticity

Question 4.
Choose the wrong statement from the following.
(a) Small droplets of a liquid are spherical due to surface tension
(b) Oil rises through the wick due to capillarity
(c) In drinking the cold drinks through a straw, we use the phenomenon of capillarity
(d) Gum is used to stick two surfaces. In this process we use the property of Adhesion

Answer: (c) In drinking the cold drinks through a straw, we use the phenomenon of capillarity

Question 5.
The height of a liquid in a fine capillary tube
(a) Increases with an increase in the density of a liquid
(b) Decreases with a decrease in the diameter of the tube
(c) Decreases with an increase in the surface tension
(d) Increases as the effective value of acceleration due to gravity is decreased

Answer: (d) Increases as the effective value of acceleration due to gravity is decreased

Question 6.
At critical temperature, the surface tension of a liquid
(a) Is zero
(b) Is infinity
(c) Is the same as that at any other temperature
(d) Can not be determined

Question 7.
A capillary tube when immersed vertically in a liquid records a rise of 3 cm. if the tube is immersed in the liquid at an angle of 60° with the vertical, then length of the liquid column along the tube will be
(a) 2 cm
(b) 3 cm
(c) 6 cm
(d) 9 cm

Question 8.
When the angle of contact between a solid and a liquid is 90°, then
(a) Cohesive force > Adhesive force
(b) Cohesive force < Adhesive force
(c) Cohesive force = Adhesive force
(d) Cohesive force >> Adhesive force

Question 9.
Water rises up to a height of 5 cm in a capillary tube of radius 2 mm. what is the radius of the radius of the capillary tube if the water rises up to a height of 10 cm in another capillary?
(a) 4 mm
(b) 1 mm
(c) 3 mm
(d) 1 cm

Question 10.
If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is
(a) Acute angle
(b) Obtuse angle
(c) 90°
(d) 0°

Question 11.
A number of small drops of mercury coalesce adiabatically to form a single drop. The temperature of drop
(a) Increases
(b) Is infinite
(c) Remains unchanged
(d) May decrease or increase depending upon size

Answer: (d) May decrease or increase depending upon size

Question 12.
Surface tension of a soap solution is 1.9 × 10-2N/m. work done in blowing a bubble of 2.0 cm diameter will be
(a) 7.6 × 10-6 p J
(b) 15.2 × 10-6 p J
(c) 1.9 × 10-6 p J
(d) 1 × 10-4 p J

Answer: (b) 15.2 × 10-6 p J

Question 13.
The height of water in a capillary tube of radius 2 cm is 4 cm. what should be the radius of capillary, if the water rises to 8 cm in tube?
(a) 1 cm
(b) 0.1 cm
(c) 2 cm
(d) 4 cm

Question 14.
Water rises up to a height of 4 cm, in a capillary tube immersed vertically in water. What will be the length of water column in the capillary tube, if the tube is immersed in water, at an angle of 60° with the vertical?
(a) 4 cm
(b) 6 cm
(c) 8 cm
(d) 2 cm

Question 15.
The surface of water in contact with glass wall is
(a) Plane
(b) concave
(c) convex
(d) Both b and c

Question 16.
5 g of water rises in the bore of capillary tube when it is dipped in water. If the radius of bore capillary tube is doubled, the mass of water that rises in the capillary tube above the outside water level is
(a) 1.5 g
(b) 10 g
(c) 5 g
(d) 15 g

Question 17.
The height of a liquid in a fine capillary tube
(a) Increases with an increase in the density of a liquid
(b) Decreases with a decrease in the diameter of the tube
(c) Decreases with an increase in the surface tension
(d) Increases as the effective value of acceleration due to gravity is decreased

Answer: (d) Increases as the effective value of acceleration due to gravity is decreased

Question 18.
If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is
(a) Acute angle
(b) Obtuse angle
(c) 90°
(d) 0°

Question 19.
Water rises up to a height h, in a capillary tube of radius r. the mass of the water lifted in the capillary tube is M. if the radius of the capillary tube is doubled, the mass of water that will rise in the capillary tube will be
(a) M
(b) 2M
(c) M/2
(d) 4M

Question 20.
Two soap bubbles have radii in the ratio of 4 : 3. What is the ratio of work done to below these bubbles?
(a) 4 : 3
(b) 16 : 9
(c) 09 : 16
(d) 3 : 4