Surface Irregularities

Q.

Consider the following statements:

Statement 1: Rough surfaces generally have more friction between them.
Statement 2: When we attempt to slide one surface over another, we have to apply a force to overcome interlocking between the irregularities present on the surfaces.

Choose the correct option.

1. Statement 1 is correct but statement 2 is incorrect.

2. Both the statements are correct.

3. Statement 1 is incorrect but statement 2 is correct.

4. Both the statements are incorrect.

Q. Statement 1: If thrust increases, interlocking and adhesion both increase.
Statement 2: Plowing effect is seen when a soft object deforms due to another object in its contact.
Choose the correct option.

1. Only statement 1 is correct.
2. Only statement 2 is correct.
3. Both statements are incorrect.
4. Both statements are correct.

Q. Which of the following has the most abrasive or irregular surface?

1. Stainless Steel
2. Surface of an ice-cube
3. Sandpaper
4. Mirror

Q. Which of the following bodies will experience least drag while moving through air?

1. Ring shaped flow
2. Streamline shaped flow
3. Star shaped flow
4. Dumbell shaped flow

Q.

For the same pair of bodies, the correct relation between different types of friction is:

1. Static friction > rolling friction > sliding friction.
2. Sliding friction > static friction > rolling friction.

3. Static friction > sliding friction > rolling friction.

4. Sliding friction > rolling friction > static friction.

Q.

What happens to interlocking between two surfaces in contact when a lubricant is applied between them?

1. Interlocking decreases
2. Cannot be determined

3. No change

4. Interlocking increases

Q.

Arrange the following in increasing order of surface roughness:

• Sandpaper
• Polished steel
• Cardboard

1. Sandpaper < Cardboard < Polished steel
2. Polished steel < Cardboard < Sandpaper
3. Polished steel < Sandpaper < Cardboard
4. Cardboard < Sandpaper < Polished steel

Q. is due to presence of irregularities on a surface.

1. Softness
2. Hardness
3. Roughness
4. Smoothness

Q. Which of the following objects have smooth surfaces?

1. Glass tumbler
2. Silk cloth
3. Rusty iron piece
4. Plane mirror
5. Sandpaper
6. Uneven rock
7. Marble tile
8. Granite tile

Q. Which of the following objects offer less friction?

1. Glass tumbler
2. Sand paper
3. Uneven rock
4. Silk cloth