Metals are good conductors of electricity because _____.

1. 1. They contain free electrons
   2. they have high melting point
   3. they atoms are lightly packed
   4. None of these

A red light is used in a traffic signal because _____.

1. 1. It is beautiful
   2. It is visible to people even with bad eyesight
   3. It has the longest wavelength and can be easily noticed from a long distance
   4. None of these

The dynamo converts _____.

1. 1. Mechanical energy into magnetic energy
   2. Electrical energy into mechanical energy
   3. Mechanical energy into electrical energy
   4. None of these

Which of the following does not admit any division?

1. 1. Molecules
   2. Atom
   3. Compound
   4. All

Which metal is commonly used as an electromagnet?

1. 1. Copper
   2. Nickel
   3. Cobalt
   4. Iron

Who said, ‘A body will remain at rest unless an external force acts on the body?

1. 1. Einstein
   2. Galileo
   3. Newton
   4. Archimedes

The common refrigerant used in the domestic refrigerator is _____.

1. 1. Freon/ammonia
   2. Sprit
   3. Neon
   4. None of these

A plant with green leaves placed in red light will appear _____.

1. 1. Green
   2. Black
   3. Red
   4. Violet

When load is lifted from ground toa certain height, some work is done and energy is used up This is energy is converted into _____.

1. 1. Heat as well as potential energy
   2. Heat and dissipated
   3. Internal energy of the body
   4. Potential energy of the body

Sonar works on the principle of _____.

1. 1. Reflection of radio-waves
   2. Absorption of sound
   3. Reflection of sound
   4. None of these