142967
One end of towel dips in a bucket with full of water and other end hang over the bucket. It is found that after sometime the towel becomes fully wet. It happens because
1 viscosity of water is high
2 of capillary action of cotton threads
3 of gravitational force
4 of evaporation of water
Explanation:
B If one end of a towel is dipped into the bucket, it would act as a capillary. So, after sometime the towel becomes fully wet. Capillary action also known as capillarity or capillary motion or wicking. Capillary action occurs due to the liquids cohesive force and because of the adhesive force existing between the material (cotton thread) and liquids.
MHT-CET 2019
Mechanical Properties of Fluids
142970
A vertical glass capillary tube, open at both ends, contains some water. Which of the following shapes may be taken by the water in the tube?
1
2
3
4
Explanation:
A The shape of the water in a capillary tube is decided by the external pressure on the water. In the upper part, the pressure of atmosphere (air) is greater than pressure inside the water, so the result, water surface gets a concave shape and tries to anticipate the downward force due to excess pressure. So the balanced force, Component of surface tension $=$ atmospheric pressure For lower side shape, both the weight of the water and atmospheric pressure applies a force in downward direction, in order to anticipate this large force, the water surface gets convex shape (look from outside). i.e, Upward direction component of surface tension $=$ Net downward force.
Karnataka CET-2001
Mechanical Properties of Fluids
142976
A $20 \mathrm{~cm}$ long capillary tube is dipped vertically in water and the liquid rises up to $10 \mathrm{~cm}$. If the entire system is kept is a freely falling platform, the length of the water column in the tube will be
1 $5 \mathrm{~cm}$
2 $10 \mathrm{~cm}$
3 $15 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Explanation:
D We know, Height raised by liquid in capillary tube, $h=\frac{2 \mathrm{~T} \cos \theta}{\rho g r}$ On freely falling platform a body experience weightlessness because gravitation force on water will be zero. Surface tension will not be cancelled by any other force. So, the liquid will rise up to length of the capillary. i.e, $\mathrm{g}=0 \Rightarrow \mathrm{h} \rightarrow \infty$ Hence, height raised by the liquid will be $20 \mathrm{~cm}$.
WB JEE 2015
Mechanical Properties of Fluids
142984
A liquid rises in a capillary tube if the angle of contact is:
1 acute
2 obtuse
3 $\pi / 2$
4 $\pi$
Explanation:
A We know, When $\theta \lt 90^{\circ}$ (acute), the liquid in capillary tube will rise. When $\theta>90^{\circ}$ (obtuse), the liquid in capillary tube will fall.
142967
One end of towel dips in a bucket with full of water and other end hang over the bucket. It is found that after sometime the towel becomes fully wet. It happens because
1 viscosity of water is high
2 of capillary action of cotton threads
3 of gravitational force
4 of evaporation of water
Explanation:
B If one end of a towel is dipped into the bucket, it would act as a capillary. So, after sometime the towel becomes fully wet. Capillary action also known as capillarity or capillary motion or wicking. Capillary action occurs due to the liquids cohesive force and because of the adhesive force existing between the material (cotton thread) and liquids.
MHT-CET 2019
Mechanical Properties of Fluids
142970
A vertical glass capillary tube, open at both ends, contains some water. Which of the following shapes may be taken by the water in the tube?
1
2
3
4
Explanation:
A The shape of the water in a capillary tube is decided by the external pressure on the water. In the upper part, the pressure of atmosphere (air) is greater than pressure inside the water, so the result, water surface gets a concave shape and tries to anticipate the downward force due to excess pressure. So the balanced force, Component of surface tension $=$ atmospheric pressure For lower side shape, both the weight of the water and atmospheric pressure applies a force in downward direction, in order to anticipate this large force, the water surface gets convex shape (look from outside). i.e, Upward direction component of surface tension $=$ Net downward force.
Karnataka CET-2001
Mechanical Properties of Fluids
142976
A $20 \mathrm{~cm}$ long capillary tube is dipped vertically in water and the liquid rises up to $10 \mathrm{~cm}$. If the entire system is kept is a freely falling platform, the length of the water column in the tube will be
1 $5 \mathrm{~cm}$
2 $10 \mathrm{~cm}$
3 $15 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Explanation:
D We know, Height raised by liquid in capillary tube, $h=\frac{2 \mathrm{~T} \cos \theta}{\rho g r}$ On freely falling platform a body experience weightlessness because gravitation force on water will be zero. Surface tension will not be cancelled by any other force. So, the liquid will rise up to length of the capillary. i.e, $\mathrm{g}=0 \Rightarrow \mathrm{h} \rightarrow \infty$ Hence, height raised by the liquid will be $20 \mathrm{~cm}$.
WB JEE 2015
Mechanical Properties of Fluids
142984
A liquid rises in a capillary tube if the angle of contact is:
1 acute
2 obtuse
3 $\pi / 2$
4 $\pi$
Explanation:
A We know, When $\theta \lt 90^{\circ}$ (acute), the liquid in capillary tube will rise. When $\theta>90^{\circ}$ (obtuse), the liquid in capillary tube will fall.
142967
One end of towel dips in a bucket with full of water and other end hang over the bucket. It is found that after sometime the towel becomes fully wet. It happens because
1 viscosity of water is high
2 of capillary action of cotton threads
3 of gravitational force
4 of evaporation of water
Explanation:
B If one end of a towel is dipped into the bucket, it would act as a capillary. So, after sometime the towel becomes fully wet. Capillary action also known as capillarity or capillary motion or wicking. Capillary action occurs due to the liquids cohesive force and because of the adhesive force existing between the material (cotton thread) and liquids.
MHT-CET 2019
Mechanical Properties of Fluids
142970
A vertical glass capillary tube, open at both ends, contains some water. Which of the following shapes may be taken by the water in the tube?
1
2
3
4
Explanation:
A The shape of the water in a capillary tube is decided by the external pressure on the water. In the upper part, the pressure of atmosphere (air) is greater than pressure inside the water, so the result, water surface gets a concave shape and tries to anticipate the downward force due to excess pressure. So the balanced force, Component of surface tension $=$ atmospheric pressure For lower side shape, both the weight of the water and atmospheric pressure applies a force in downward direction, in order to anticipate this large force, the water surface gets convex shape (look from outside). i.e, Upward direction component of surface tension $=$ Net downward force.
Karnataka CET-2001
Mechanical Properties of Fluids
142976
A $20 \mathrm{~cm}$ long capillary tube is dipped vertically in water and the liquid rises up to $10 \mathrm{~cm}$. If the entire system is kept is a freely falling platform, the length of the water column in the tube will be
1 $5 \mathrm{~cm}$
2 $10 \mathrm{~cm}$
3 $15 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Explanation:
D We know, Height raised by liquid in capillary tube, $h=\frac{2 \mathrm{~T} \cos \theta}{\rho g r}$ On freely falling platform a body experience weightlessness because gravitation force on water will be zero. Surface tension will not be cancelled by any other force. So, the liquid will rise up to length of the capillary. i.e, $\mathrm{g}=0 \Rightarrow \mathrm{h} \rightarrow \infty$ Hence, height raised by the liquid will be $20 \mathrm{~cm}$.
WB JEE 2015
Mechanical Properties of Fluids
142984
A liquid rises in a capillary tube if the angle of contact is:
1 acute
2 obtuse
3 $\pi / 2$
4 $\pi$
Explanation:
A We know, When $\theta \lt 90^{\circ}$ (acute), the liquid in capillary tube will rise. When $\theta>90^{\circ}$ (obtuse), the liquid in capillary tube will fall.
142967
One end of towel dips in a bucket with full of water and other end hang over the bucket. It is found that after sometime the towel becomes fully wet. It happens because
1 viscosity of water is high
2 of capillary action of cotton threads
3 of gravitational force
4 of evaporation of water
Explanation:
B If one end of a towel is dipped into the bucket, it would act as a capillary. So, after sometime the towel becomes fully wet. Capillary action also known as capillarity or capillary motion or wicking. Capillary action occurs due to the liquids cohesive force and because of the adhesive force existing between the material (cotton thread) and liquids.
MHT-CET 2019
Mechanical Properties of Fluids
142970
A vertical glass capillary tube, open at both ends, contains some water. Which of the following shapes may be taken by the water in the tube?
1
2
3
4
Explanation:
A The shape of the water in a capillary tube is decided by the external pressure on the water. In the upper part, the pressure of atmosphere (air) is greater than pressure inside the water, so the result, water surface gets a concave shape and tries to anticipate the downward force due to excess pressure. So the balanced force, Component of surface tension $=$ atmospheric pressure For lower side shape, both the weight of the water and atmospheric pressure applies a force in downward direction, in order to anticipate this large force, the water surface gets convex shape (look from outside). i.e, Upward direction component of surface tension $=$ Net downward force.
Karnataka CET-2001
Mechanical Properties of Fluids
142976
A $20 \mathrm{~cm}$ long capillary tube is dipped vertically in water and the liquid rises up to $10 \mathrm{~cm}$. If the entire system is kept is a freely falling platform, the length of the water column in the tube will be
1 $5 \mathrm{~cm}$
2 $10 \mathrm{~cm}$
3 $15 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Explanation:
D We know, Height raised by liquid in capillary tube, $h=\frac{2 \mathrm{~T} \cos \theta}{\rho g r}$ On freely falling platform a body experience weightlessness because gravitation force on water will be zero. Surface tension will not be cancelled by any other force. So, the liquid will rise up to length of the capillary. i.e, $\mathrm{g}=0 \Rightarrow \mathrm{h} \rightarrow \infty$ Hence, height raised by the liquid will be $20 \mathrm{~cm}$.
WB JEE 2015
Mechanical Properties of Fluids
142984
A liquid rises in a capillary tube if the angle of contact is:
1 acute
2 obtuse
3 $\pi / 2$
4 $\pi$
Explanation:
A We know, When $\theta \lt 90^{\circ}$ (acute), the liquid in capillary tube will rise. When $\theta>90^{\circ}$ (obtuse), the liquid in capillary tube will fall.
