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

The most non-polluting and efficient lighting device is :

IEA is the short form of :

Why should we conserve the non-renewable sources of energy?

State the main difference between the renewable and non-renewable sources of energy.

Explain why is it no wise to regard wood as a renewable sources of energy.

Why are fossil fuels called non-renewable sources of energy?

Why is charcoal considered better fuel than wood?

Name two forms of sea energy.

Name the major constituent of natural gas.

Define metre according to the old definition.

Define metre in terms of the wavelength of light.

Why is the metre length in terms of the wavelength of light considered more accurate?

Is it possible to increase the degree of accuracy by mathematical manipulations? Support your answer by an example.

The final result of the calculation in an experiment is 125,347,200. Express the number in term of significant place when accuracy is between 1 and 10

The final result of the calculation in an experiment is 125,347,200. Express the number in term of significant place when accuracy is between 1 and 100

The final result of the calculation in an experiment is 125,347,200. Express the number in term of significant place when accuracy is between 1 and 1000

The main scale of vernier callipers has 10 divisions in a centimetre and 10 vernier scale divisions coincide with 9 main scale divisions. Calculate

1. pitch
2. L.C. of vernier callipers.

In a vernier callipers, 19 main scale divisions coincide with 20 vernier scale divisions. If the main scale has 20 divisions in a centimetre, calculate

1. pitch
2. L.C. of vernier callipers.

Figure shows the position of vernier scale while measuring the external length of a wooden cylinder.

1. What is the length recorded by the main scale?
   
2. Which reading of vernier scale coincides with the main scale?
3. Calculate the length.

In figure for vernier callipers, calculate the length recorded.