Which of the following instruments can measure contact angle of a liquid drop placed on a surface?
Show Hint
- Goniometer
- Pycnometer
- Soxhlet apparatus
- Rheometer
The Correct Option is A
Solution and Explanation
- A Goniometer is specifically designed to measure the contact angle by analyzing the profile of a liquid drop placed on a solid surface. It captures the drop image and calculates the angle formed at the three-phase boundary (solid–liquid–air). Hence, (A) is correct.
- A Pycnometer is used to measure the density of liquids. It has no relation to contact angle measurement, so (B) is incorrect.
- A Soxhlet apparatus is used for continuous extraction of compounds (mainly in chemistry/food industry applications). It does not measure contact angles. Thus, (C) is incorrect.
- A Rheometer is used to study the flow and deformation behavior (rheology) of fluids. It measures viscosity and viscoelastic properties, not contact angle. Hence, (D) is incorrect.
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Identify the option that has the most appropriate sequence such that a coherent paragraph is formed:
Statement:
P. At once, without thinking much, people rushed towards the city in hordes with the sole aim of grabbing as much gold as they could.
Q. However, little did they realize about the impending hardships they would have to face on their way to the city: miles of mud, unfriendly forests, hungry beasts, and inimical local lords—all of which would reduce their chances of getting gold to almost zero.
R. All of them thought that easily they could lay their hands on gold and become wealthy overnight.
S. About a hundred years ago, the news that gold had been discovered in Kolar spread like wildfire and the whole State was in raptures.
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The total pore volume (in rb) of the reservoir is:
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