English Medium Class 9 - CBSE Question Bank Solutions for Science

How does the average temperature of Earth remain fairly steady?

Name the device or machine which convert :
Mechanical energy into electrical energy.

Name the device or machine which convert :
Chemical energy into electrical energy.

Name the device or machine which convert :
Electrical energy into heat energy.

Name the device or machine which convert :
Light energy into electrical energy.

Name the device or machine which convert :
Electrical energy into light energy.

Name the device or machine which convert :
Electrical energy into sound energy.

Name the device or machine which convert :
Heat energy into kinetic energy (or mechanical energy).

Name the device or machine which convert :
Chemical energy into kinetic energy (or mechanical energy).

Name the device or machine which convert :
Chemical energy into heat energy.

Name the device or machine which convert :
light energy into heat energy.

Fill in the blank with suitable word:
The electricity meter installed in our homes measure electrical energy in the units of ___________.

Fill in the blanks with suitable words:
When a ball is thrown upwards, ___________ energy is transformed into ___________ energy.

Fill in the blanks with suitable words :
The principle of ___________ of energy says energy can be transformed from one form to another, but it cannot be ___________ or ___________.

How much electrical energy in joules does a 100 watt lamp consume : in 1 second? 

How much electrical energy in joules does a 100 watt lamp consume :  in 1 minute?

Five electric fans of 120 watts each are used for 4 hours. Calculate the electrical energy consumed in kilowatt-hours.