The dynamo converts

• mechanical energy into magnetic energy

• mechanical energy into electrical energy

• electrical energy into mechanical energy

• None of the above

The velocity of sound in moist air is more than in dry air because the moist air has

• less pressure than dry air

• more density than dry air

• more pressure than dry air

• less density than dry air

Rainbow formation is due to

• absorption of sunlight by water droplets

• diffusion of sunlight through water droplets

• ionisation of water droplets

• refraction and reflection of sunlight by water droplets

To an astronaut in space the sky will appear to be

• violet

• red

• blue

• black

Natural radioactivity was discovered by

• Rutherford

• Marie Curie

• Henri Becquerel

• Enrico Fermi

For a missile launched with a velocity, less than the Earth's escape velocity, the total energy is

• negative

• zero

• positive

• Either (a) or (c)

'Farad' is the unit of

• resistance

• conductance

• capacitance

• inductance

A fuse wire is characterized by

• high resistance and high melting point

• high resistance and low melting point

• low resistance and low melting point

• low resistance and high melting point

Electric current is measured using which of the following instrument?

• Ammeter

• Voltmeter

• Anemometer

• Watt meter

The least penetrating power ray is

• γ - Ray

• α - Ray

• X - Ray

• β - Ray