(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

What is a block and tackle system of pulleys?

Name the type of single pulley that can act as a force multiplier. Draw a labeled diagram of the pulley mentioned by you.

Give a reason for the following:

In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.

Give reason for the following:

 The efficiency of a pulley is always less than 100%

Give reason for the following:

In case of a block and tackle system, the mechanical advantage increases with the increase in the number of pulleys.

Name a machine which is used to:

change the direction of force applied.

Write two uses of pulleys. Is pulley a force multiplier?

Fig shown a block and tackles system of pulleys used to lift a load.

(i) How many strands of tackle are supporting the load?

(ii) Draw arrows to represent tension in each stand.

(iii) What is the mechanical advantage of the system?

(iv) When load is pulled up by a distance 1 m how far does the effort end move?

What is a block and tackle system of pulleys?

(a)  Fig represents an incomplete diagram of a simple string pulley      system. Copy this diagram on a new page and complete it and mark where the effort must be applied to lift the load.
(b) What is the velocity ratio of this system?
(c) If the pulley system is 80% efficient and the load is 720 N, then
    (i) What effort must be applied to lift the load?
    (ii) What work must be done must be done in lifting the load through   a distance of 2 m using this machine?

1. 1. the angle of refraction and
   2. the angle of deviation for the ray?