On the Moon, an astronaut cannot drink lemonade with the help of straw because

• acceleration due to gravity on the Moon is less

• there is no atmosphere on the Moon

• lemonade evaporates instantaneously on the Moon

• None of the above

What type of mirror is used in a view finding mirror of a vehicle?

• Paraboloidal mirror

• Convex mirror

• Plane mirror

• Concave mirror

Which colour/colour of light has the highest velocity through vaccum?

• Blue

• Red

• Green

• All of these

Earth is a very big magnet. In which direction does its magnetic field extend?

• East to West

• West to East

• North to South

• South to North

The function of ball bearings in a wheel is

• to increase friction

• to convert kinetic friction into rolling friction

• to convert static friction into kinetic friction

• just for convenience

Lambert's law is related to

• Reflection

• Refraction

• Interference

• Illumination

97.

The modulus of rigidity is the ratio of

• longitudinal stress to longitudinal strain

• volume stress to volume strain

• shearing stress to shearing strain

• tensile stress to tensile strain

The propagation of sound waves in a gas involves

• adiabatic compression and rarefaction

• isothermal compression and rarefaction

• isochoric compression and rarefaction

• isobaric compression and rarefaction

A concave lens always forms an image which is

• real and erect

• virtual and erect

• real and inverted

• virtual and inverted

If input frequency of a full wave rectifier be n, then output frequency would be

• n/2

• n

• 3n/2

• 2n