Practice MCQ Questions and answers on Physics-GK

Lightning is produced when strong opposite charges in different clouds break down the resistance offered by the intervening air.

The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the most common materials used in lightning protection.

Good conductor of electricity is graphite.

One Kilowatt hour is equal to 3.6 Mega Joule.

Aluminium is good conductors of electricity.

Pure water is a bad conductor of electricity. Pure water does not contain any impurities or ions resulting in neutral ions present in it. In the absence of electrons no solution or water can conduct electricity as ions carry electric charge and conduct electricity.

The most electrically conductive metal is silver.

Salt water is a conductor of electricity.

Birds don't get electrocuted on power lines because electricity does not move through their bodies when they sit on them. When the bird sits with both its feet on the electrical wire, their legs have an equal electrical potential so the electricity will not move throughout the bird's body.

The fuse in our domestic electric circuit melts when there is a high rise in current.