Radio waves are _____.

1. 1. Head waves
   2. Water waves
   3. Sound waves
   4. Electromagnetic waves

The wave which do not require any medium is _____.

1. 1. Water waves
   2. Electromagnetic waves
   3. Sound wave
   4. Air waves

A semi-conductor is also used as _____.

1. 1. Rectified
   2. Capacitor
   3. Electronic motor
   4. Transformer

Lightning is formed when_____.

1. 1. Water vapor pro0duces electricity in the clouds
   2. Clouds strike against impurities in air and the friction burns up these impurities
   3. strong opposite charges in different clouds breakdown the resistance offered by the intervening air
   4. Similar charges of electricity rush towards each other and then get repelled

The atmosphere exerts enormous pressure on us. But we do not feel it.

1. 1. The surface area of our head is very small
   2. Our blood exerts a pressure slightly more than that of the atmosphere
   3. We are used to it
   4. Our bones are very strong and can withstand this pressure

According to the definition of 1 KWh, a 100 watt bulb consumes one unit of electricity in _____.

1. 1. 2 hours
   2. 5 hours
   3. 10 hours
   4. 8 hours

One kilowatt-hour is the amount of electrical energy that is consumed by 1000 watt appliance in _____.

1. 1. 1 hour
   2. 30 minutes
   3. 45 minutes
   4. 1 hour and 15 minutes

In BTU system one BTU is equal to _____.

1. 1. 1055 Joule
   2. 2055 Joule
   3. 2155 Joule
   4. 1155 Joule

In which system of units are gas bills charged?

1. 1. SI
   2. BTU
   3. CGS
   4. None of these

Units of electricity consumed by 2500 watt air-conditioner in one hour are _____.

1. 1. 2.5 units
   2. 25 units
   3. 2.36 units
   4. 0.25 units