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

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

Give two reasons why the efficiency of a single movable pulley system is not 100%.

In which direction does the force need to applied, when a single pulley is used with a mechanical advantage greater than one? How can you change the direction of force applied without altering its mechanical advantage? Draw a labelled diagram of the system.

The diagram below shows a pulley arrangement.

1. Name the pulleys A and B.
2. In the diagram, mark the direction of tension on each strand of string.
3. What is the purpose of the pulley B?
4. If the tension is T, deduce the relation between
   1. T and E, and
   2. E and L.
5. What is the velocity ratio of the arrangement?
6. Assuming that the efficiency of the system is 100%, what is the mechanical advantage?

Differentiate between a single fixed pulley and a single movable pulley.

The diagram below shows an arrangement of three pulleys A, B, and C. The load is marked as L and the effort as E.

1. Name the Pulleys A, B, and C.
2. Mark in the diagram the directions of load (L), effort (E) and tension T₁ and T₂ in the two strings.
3. How are the magnitudes of L and E related to the tension T₁?
4. Calculate the mechanical advantage and velocity ratio of the arrangement.
5. What assumptions have you made in parts (c) and (d)?

Draw a diagram of a combination of three movable pulleys and one fixed pulley to lift up a load. In the diagram, show the directions of load, effort and tension in each strand. Find:

1. mechanical advantage,
2. Velocity ratio and
3. efficiency of the combination in ideal situation.

What is a block and tackle system of pulleys?

A block and tackle pulley system has a velocity ratio 5. Draw a labelled diagram of this system.  In your diagram, indicate clearly the points of application and the directions of the load and effort.

Give reason for the following:
 In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.

Give reason for the following:

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

What is the purpose of a switch in a circuit?

Give reason for the following:

The lower block of a block and tackle pulley system must be of negligible weight

A switch is not touched with wet hands while putting it on or off. Give a reason for your answer.

The mechanical advantage of an ideal single movable pulley is ______.

The following diagram shows three lamps and three switches 1, 2 and 3 connected with two cells.

1. Name the switch / switches to be closed so as to light all the three lamps.
2. How are the lamps connected: in series or in parallel?

A pulley system has a velocity ratio 3. Draw a diagram showing the point of application and direction of load (L), effort (E) and tension (T). It lifts a load of 150 N by an effort of 60 N. Calculate its mechanical advantage. Is the pulley system ideal? Give reason.

State two advantages of an electromagnet over a permanent magnet.

Write the expressions for the equivalent resistance R of three resistors R₁, R₂ and R₃ joined in

1. parallel
2. series 

A light ray in passing from water to a medium

(a) speeds up

(b) slows down. In each case, give one example of the medium.