142800
An elliptically shaped ring of dimensions shown in figure just touches the horizontal surface of a liquid of surface tension $S$. The force required to pull the away from the liquid surface is
A Internal circumference of the $\text { ring }=2 \pi r_{1}=2 \pi \sqrt{a_{1} b_{1}}$ External circumference of the ring $=2 \pi r_{2}=2 \pi \sqrt{a_{2} b_{2}}$ Hence, force required $\mathrm{F} =2 \pi S \sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+2 \pi \mathrm{S} \sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}$ $=2 \pi \mathrm{S}\left(\sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+\sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}\right)$
JCECE-2015
Mechanical Properties of Fluids
142801
Two glass plates are separated by water, if surface tension of water is 75 dynes/cm and area of each plate wetted by water is $8 \mathrm{~cm}^{2}$ and the distance between the plates is $0.12 \mathrm{~mm}$, then the force applied to separate the two plates is
1 $10^{2}$ dyne
2 $10^{4}$ dyne
3 $10^{5}$ dyne
4 $10^{6}$ dyne
Explanation:
C Given, Surface tension $(T)=75$ dynes $/ \mathrm{cm}$ Area of each plate $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Distance between the plate $(\mathrm{d})=0.12 \mathrm{~mm}=0.012 \mathrm{~cm}$ Pressure difference $(\Delta \mathrm{P})=\frac{2 \mathrm{~T}}{\mathrm{~d}}$ Area $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Force $\mathrm{F}$ required to separate the two plates $\mathrm{F} =\Delta \mathrm{P} \times \mathrm{A}$ $=\frac{2 \mathrm{~T}}{\mathrm{~d}} \times \mathrm{A}=\frac{2 \times 75 \times 8}{0.012}=10^{5} \text { dyne }$
JCECE-2007
Mechanical Properties of Fluids
142802
Assertion: Surface tension of all lubricating oils and paints is kept high. Reason: Due to high value of surface tension the fluids get damaged.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
D The surface tension of oils and paints is kept low and it can spread over large area easily and also faster.
AIIMS-05.2018(M)
Mechanical Properties of Fluids
142803
Assertion: A small iron needle sinks in water while a large iron ship floats. Reason: The shape of iron needle is like a flat surface while the shape of a ship is that which makes it easier to float.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
C The density of water is less than the density of iron, therefore the weight of iron is more than weight of water displaced by it. The weight of water displaced by the ship is equal to its weight, so it floats in water.
142800
An elliptically shaped ring of dimensions shown in figure just touches the horizontal surface of a liquid of surface tension $S$. The force required to pull the away from the liquid surface is
A Internal circumference of the $\text { ring }=2 \pi r_{1}=2 \pi \sqrt{a_{1} b_{1}}$ External circumference of the ring $=2 \pi r_{2}=2 \pi \sqrt{a_{2} b_{2}}$ Hence, force required $\mathrm{F} =2 \pi S \sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+2 \pi \mathrm{S} \sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}$ $=2 \pi \mathrm{S}\left(\sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+\sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}\right)$
JCECE-2015
Mechanical Properties of Fluids
142801
Two glass plates are separated by water, if surface tension of water is 75 dynes/cm and area of each plate wetted by water is $8 \mathrm{~cm}^{2}$ and the distance between the plates is $0.12 \mathrm{~mm}$, then the force applied to separate the two plates is
1 $10^{2}$ dyne
2 $10^{4}$ dyne
3 $10^{5}$ dyne
4 $10^{6}$ dyne
Explanation:
C Given, Surface tension $(T)=75$ dynes $/ \mathrm{cm}$ Area of each plate $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Distance between the plate $(\mathrm{d})=0.12 \mathrm{~mm}=0.012 \mathrm{~cm}$ Pressure difference $(\Delta \mathrm{P})=\frac{2 \mathrm{~T}}{\mathrm{~d}}$ Area $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Force $\mathrm{F}$ required to separate the two plates $\mathrm{F} =\Delta \mathrm{P} \times \mathrm{A}$ $=\frac{2 \mathrm{~T}}{\mathrm{~d}} \times \mathrm{A}=\frac{2 \times 75 \times 8}{0.012}=10^{5} \text { dyne }$
JCECE-2007
Mechanical Properties of Fluids
142802
Assertion: Surface tension of all lubricating oils and paints is kept high. Reason: Due to high value of surface tension the fluids get damaged.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
D The surface tension of oils and paints is kept low and it can spread over large area easily and also faster.
AIIMS-05.2018(M)
Mechanical Properties of Fluids
142803
Assertion: A small iron needle sinks in water while a large iron ship floats. Reason: The shape of iron needle is like a flat surface while the shape of a ship is that which makes it easier to float.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
C The density of water is less than the density of iron, therefore the weight of iron is more than weight of water displaced by it. The weight of water displaced by the ship is equal to its weight, so it floats in water.
142800
An elliptically shaped ring of dimensions shown in figure just touches the horizontal surface of a liquid of surface tension $S$. The force required to pull the away from the liquid surface is
A Internal circumference of the $\text { ring }=2 \pi r_{1}=2 \pi \sqrt{a_{1} b_{1}}$ External circumference of the ring $=2 \pi r_{2}=2 \pi \sqrt{a_{2} b_{2}}$ Hence, force required $\mathrm{F} =2 \pi S \sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+2 \pi \mathrm{S} \sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}$ $=2 \pi \mathrm{S}\left(\sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+\sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}\right)$
JCECE-2015
Mechanical Properties of Fluids
142801
Two glass plates are separated by water, if surface tension of water is 75 dynes/cm and area of each plate wetted by water is $8 \mathrm{~cm}^{2}$ and the distance between the plates is $0.12 \mathrm{~mm}$, then the force applied to separate the two plates is
1 $10^{2}$ dyne
2 $10^{4}$ dyne
3 $10^{5}$ dyne
4 $10^{6}$ dyne
Explanation:
C Given, Surface tension $(T)=75$ dynes $/ \mathrm{cm}$ Area of each plate $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Distance between the plate $(\mathrm{d})=0.12 \mathrm{~mm}=0.012 \mathrm{~cm}$ Pressure difference $(\Delta \mathrm{P})=\frac{2 \mathrm{~T}}{\mathrm{~d}}$ Area $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Force $\mathrm{F}$ required to separate the two plates $\mathrm{F} =\Delta \mathrm{P} \times \mathrm{A}$ $=\frac{2 \mathrm{~T}}{\mathrm{~d}} \times \mathrm{A}=\frac{2 \times 75 \times 8}{0.012}=10^{5} \text { dyne }$
JCECE-2007
Mechanical Properties of Fluids
142802
Assertion: Surface tension of all lubricating oils and paints is kept high. Reason: Due to high value of surface tension the fluids get damaged.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
D The surface tension of oils and paints is kept low and it can spread over large area easily and also faster.
AIIMS-05.2018(M)
Mechanical Properties of Fluids
142803
Assertion: A small iron needle sinks in water while a large iron ship floats. Reason: The shape of iron needle is like a flat surface while the shape of a ship is that which makes it easier to float.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
C The density of water is less than the density of iron, therefore the weight of iron is more than weight of water displaced by it. The weight of water displaced by the ship is equal to its weight, so it floats in water.
NEET Test Series from KOTA - 10 Papers In MS WORD
WhatsApp Here
Mechanical Properties of Fluids
142800
An elliptically shaped ring of dimensions shown in figure just touches the horizontal surface of a liquid of surface tension $S$. The force required to pull the away from the liquid surface is
A Internal circumference of the $\text { ring }=2 \pi r_{1}=2 \pi \sqrt{a_{1} b_{1}}$ External circumference of the ring $=2 \pi r_{2}=2 \pi \sqrt{a_{2} b_{2}}$ Hence, force required $\mathrm{F} =2 \pi S \sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+2 \pi \mathrm{S} \sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}$ $=2 \pi \mathrm{S}\left(\sqrt{\mathrm{a}_{1} \mathrm{~b}_{1}}+\sqrt{\mathrm{a}_{2} \mathrm{~b}_{2}}\right)$
JCECE-2015
Mechanical Properties of Fluids
142801
Two glass plates are separated by water, if surface tension of water is 75 dynes/cm and area of each plate wetted by water is $8 \mathrm{~cm}^{2}$ and the distance between the plates is $0.12 \mathrm{~mm}$, then the force applied to separate the two plates is
1 $10^{2}$ dyne
2 $10^{4}$ dyne
3 $10^{5}$ dyne
4 $10^{6}$ dyne
Explanation:
C Given, Surface tension $(T)=75$ dynes $/ \mathrm{cm}$ Area of each plate $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Distance between the plate $(\mathrm{d})=0.12 \mathrm{~mm}=0.012 \mathrm{~cm}$ Pressure difference $(\Delta \mathrm{P})=\frac{2 \mathrm{~T}}{\mathrm{~d}}$ Area $(\mathrm{A})=8 \mathrm{~cm}^{2}$ Force $\mathrm{F}$ required to separate the two plates $\mathrm{F} =\Delta \mathrm{P} \times \mathrm{A}$ $=\frac{2 \mathrm{~T}}{\mathrm{~d}} \times \mathrm{A}=\frac{2 \times 75 \times 8}{0.012}=10^{5} \text { dyne }$
JCECE-2007
Mechanical Properties of Fluids
142802
Assertion: Surface tension of all lubricating oils and paints is kept high. Reason: Due to high value of surface tension the fluids get damaged.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
D The surface tension of oils and paints is kept low and it can spread over large area easily and also faster.
AIIMS-05.2018(M)
Mechanical Properties of Fluids
142803
Assertion: A small iron needle sinks in water while a large iron ship floats. Reason: The shape of iron needle is like a flat surface while the shape of a ship is that which makes it easier to float.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
C The density of water is less than the density of iron, therefore the weight of iron is more than weight of water displaced by it. The weight of water displaced by the ship is equal to its weight, so it floats in water.
