Page 127 - Viva ICSE Science 4 : E-book

5. Lubricants are used to completely remove friction.

6. Friction causes wear and tear of machine parts.

C. Tick () the correct answer.

1. Rough surface has ____________.

(a) less friction (b) greater friction (c) same friction

2. For a better grip while walking, the sole of our shoes should be ___________.

(a) grooved (b) smooth (c) polished

3. It is diffi cult to walk on wet fl oor because it has ____________.
(a) no friction (b) more friction (c) less friction

4. It is diffi cult to push an iron box in comparison to wooden box of same size
because ____________.

(a) heavy objects have more friction

(b) light objects have less friction

(c) heavy objects have less friction

5. Friction between violin string and its bow produces ____________.

(a) light (b) spark (c) sound

6. Which of the following is a harmful eff ect of friction?

(a) A car can move on the road.

(b) Fire accidents can happen due to excess friction.

(c) A matchstick can be lighted.

D. Match the following.
Column A Column B

1. Striker not sliding properly (a) polish it

on the carom board
2. Doors making squeaking sound (b) put rollers

3. Not able to slide smoothly on (c) sprinkle powder
the park slide

4. Not able to pull the heavy suitcase (d) put oil

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