Multiple choice

An iron block of sides 50 cm x 8 cm x 15 cm has to be pushed along the floor. The force required will be minimum when the surface of the contact with ground is

  1. 8 cm x 15 cm

  2. 50 cm x 15 cm

  3. 50 cm x 8 cm

  4. Force is the same for all surfaces

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The frictional force is independent of the area of the contact surface. Hence the answer is (4)