Mechanical Properties of Fluids - Online Test
Q1. A wooden block is taken to the bottom of a deep, calm lake of water and then released. It rises up with a
Answer : Option B
Explaination / Solution:
The wooden block rises up with acceleration,
a =
Upthrust and mass of block will be constant.So the acceleration will also be a constant throughout mo
Q2. A man in a lift is holding a can filled with water but having a hole in its bottom. When will the drainage of water be maximum?
Answer : Option B
Explaination / Solution:
No Explaination.
Q3. In old age, arteries carrying blood in the human body, become narrow resulting in an increase in the blood pressure. This follows from
Answer : Option D
Explaination / Solution:
According to bernoulli principle for fluids: in ideal state pressure and density are inversely related or in other words a slow moving fluid exerts more pressure than a fast moving fluid. Due to narrowness and other obstruction the velocity of the flow of blood gets decreased in old age. This results in increased pressure inside the blood vessel.
Q4. Soap helps in better cleansing of clothes because
Answer : Option B
Explaination / Solution:
Water molecules have a tendency to stick together, as opposed to losing their fellow water molecules’ company and sticking to other surfaces. This happens as a result of something known as the ‘surface tension’ of water.
Surfactants are substances that help lower the surface tension of water molecules, thus ‘persuading’ them to wet things more uniformly.
Soaps (which are a type of detergent) contain surfactants in significant amounts, which help water spread uniformly over clothes.
Q5. If two soap bubbles of different radii are in communication with each other
Answer : Option A
Explaination / Solution:
No Explaination.
Q6. The surface tension of soap solution is 25 x . The excess pressure inside a soap bubble of diameter 1 cm is
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. When a soap bubble is charged, it
Answer : Option B
Explaination / Solution:
Charge will be distributed uniformly on the surface of a bubble if the bubble is charged.The bubble will expand because the charged particles uniformly distributed on it cause them to repel each other due to the electrostatic force. This will happen to both positive and negatively charged bubbles because of the charge on it.
Q8. A drop of oil is placed on the surface of water. Which of the following statements is correct?
Answer : Option A
Explaination / Solution:
when any liquid is poured onto another liquid there are different phenomena that can take place depending on the properties of liquids:In case of crude oil and water -
The two liquids are non-miscible and the first is lighter than the second. The first liquid then spreads on the surface of the second liquid forming a thin layer. The thickness of this layer depends on the properties of the two liquids. This is the case for most hydrocarbons, including both refined products and crude oil of API gravity greater than 10.
Q9. Small droplets of liquid are usually more spherical in shape than larger drops of the same liquid because
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. Water rises to a height of 16.3 cm in a capillary of height 18 cm above the water level. If the tube is suddenly cut at a height of 12 cm
Answer : Option A
Explaination / Solution:
No Explaination.
