(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Physics

Derive the equation
V²-u² = 2as

A car moving with a uniform acceleration of 10 m/s² on a straight road changes its speed from 10 m/s to 30 m/s. Find the time lapsed for the change of speed.

A body starts to slide over a horizontal surface with an initial velocity of 0.5 ms⁻¹. Due to friction, its velocity decreases at the rate of 0.05 ms⁻². How much time will it take for the body to stop?

A train is moving at a speed of 90 km/h. On applying brakes, a retardation of 2.5 ms^-2 is created. At what distance before, should the driver apply the brakes to stop the train at the station?

Name the instrument which has the least count

1 mm

A microscope has its main scale with 20 divisions in 1 cm and vernier scale with 25 divisions, the length of which is equal to the length of 24 divisions of main scale. The least count of microscope is

A stopwatch has 10 divisions graduated between the 0 and 5 s marks. What is its least count?

A vernier has 10 divisions and they are equal to 9 divisions of the main scale in length. If the main scale is calibrated in mm, what is its least count?

A microscope is provided with a main scale graduated with 20 divisions in 1 cm and a vernier scale with 50 division on it of length same as of 49 divisions of main scale. Find the least count of the microscope.

The main scale of a vernier callipers is calibrated in mm and 19 divisions of main scale are equal in length to 20 divisions of the vernier scale. In measuring the diameter of a cylinder by this instrument, the main scale reads 35 divisions and 4th division of vernier scale coincides with a main scale division. Find

(i) Least count and (ii) Radius of a cylinder.

Define the terms : oscillation

What do you understand by amplitude of simple pendulum?

Name two factors on which the time period of a simple pendulum depends. Write the relation for the time period in terms of the above named factors.

How does the time period (T) of a simple pendulum depend on its length (l)? Draw a graph showing the variation of T² with l. How will you use this graph to determine the value of g (acceleration due to gravity)?

Two simple pendulums A and B have equal lengths, but their bobs weigh 50 gf and 100 gf, respectively. What would be the ratio of their time periods? Give reasons for your answer.

State the numerical value of the frequency of oscillation of a second's pendulum. Does it depend on the amplitude of oscillations?

A seconds pendulum is taken to a place where acceleration due to the gravity falls to one-fourth. How is the time period of the pendulum affected, if at all? Give reasons. What will be its new time period?

When is a body said to be in motion?

What do you mean by motion in one direction?

Give an example of the motion of a body moving with a constant speed but with a variable velocity. Draw a diagram to represent such a motion.