EASY
7th CBSE
IMPORTANT
Earn 100

Give reasons for the following: Electromagnets are temporary magnets.
 

Important Questions on Electric Current and Its Uses

MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q V
Give reasons for the following: An electric lighting bulb (incandescent lamp) is filled with nitrogen or inert gas. 
MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q V
Give reasons for the following: The glow increases in a CFL/lighting bulb with the passage of time it is kept 'ON'.
MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VI
Differentiate between the following: An open circuit and a closed circuit

 

EASY
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VI
Differentiate between the following: A cell and a battery
MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VI
Differentiate between the following: An incandescent lamp and a fluorescent tube.
MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VII
Which metal filament is used in electric bulbs for lighting purposes and why?
MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VII

Why coils made from Nichrome are used as heating coils? 

MEDIUM
7th CBSE
IMPORTANT
S. Chand's SCIENCE For Class VII>Chapter 13 - Electric Current and Its Uses>EXERCISES>Q VII

Why do we not make use of copper or silver as heating coils?