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

The resistance of a bulb rated 60 watts/220 volts is approximately_____.

1. 1. 800 Ω
   2. 40 Ω
   3. 400 Ω
   4. 4 Ω

Why is the light of ordinary lamp hotter than the tubelight?

1. 1. It has more surface for distribution of energy
   2. It due to ionization of gases
   3. It is due to incandescence
   4. It gives white light

In an electronic watch, the component corresponding to the pendulum of pendulum clock is_____.

1. 1. Crystal oscillator
   2. Diode
   3. Transistor
   4. Balance wheel

If a bimetallic strip is heated, it will_____.

1. 1. Not bend al all
   2. bend towards the metal with lower thermal expansion coefficient
   3. Twist itself into a helix
   4. Bend towards the metal with higher thermal coefficient of expansion