Solid Friction: Viscosity MCQs with Answers PDF Download – Test 170

MCQ 846: For a sphere that is dropped into a viscous liquid, Strokes law states that the force of friction is given by:

1. 6π × radius of the sphere × coefficient of viscosity × velocity of the sphere at a particular instant
2. (6π × radius of the sphere × coefficient of viscosity) ⁄ velocity of the sphere at a particular instant
3. (6π × radius of the sphere) ⁄ (coefficient of viscosity × velocity of the sphere at a particular instant)
4. 6π ⁄ (radius of the sphere × coefficient of viscosity × velocity of the sphere at a particular instant)

MCQ 847: When the angle of incidence in denser medium is greater than the critical angle, will the total internal reflection take place or not?

1. It will
2. It won't take place
3. may take place
4. it is a property of total external angle

MCQ 848: When a solid changes its state to liquid upon heating, this change of state is termed as:

1. Melting
2. Solidification
3. Boiling
4. Condensation

MCQ 849: In solids, particles:

1. move randomly
2. vibrate about fixed position
3. vibrate and move randomly
4. move about fixed path

MCQ 850: A heater changes the temperature of room from 20 °C to 40 °C with the energy usage of 20000 J, the heat capacity of the air in the room would be:

1. 500 J K^-1
2. 1000 J K^-1
3. 1200 J K^-1
4. 1500 J K^-1