We are able to walk on earth without slipping because of

• Gravitational force

• Frictional force

• Viscous force

• Viscous force

What is the phenomenon which established the transverse nature of light?

• Reflection

• Interference

• Diffraction

• Diffraction

What is the name of the device used to convert alternating current into direct current?

• Ammeter

• Galvanometer

• Rectifier

• Rectifier

Stars twinkle but planets do not twinkle because

• they emit light of a constant intensity

• their distance from the earth does not change with time

• they are very far away from the earth resulting in decrease in intensity of light

• they are very far away from the earth resulting in decrease in intensity of light

Which of the following is not true about X-rays?

• have low penetrating power

• travel with the speed of light

• can be reflected or refracted

• can be reflected or refracted

The washing machine works on the principle of ____________.

• Dialysis

• Diffusion

• Reverse osmosis

• Reverse osmosis

A body moving in a circular path with a constant speed has a ........

• constant velocity

• variable acceleration

• constant kinetic energy

• constant kinetic energy

18.

During the motion of a projectile fired from the earth surface....

• its kinetic energy remains constant

• its momentum remains constant

• vertical component of its velocity remains constant

• vertical component of its velocity remains constant

Which of the following waves cannot be polarised?

• Radio

• Ultra violet

• Infrared

• Infrared

Two vectors are said to be equal if

• Only their magnitudes are same

• Only their directions are same

• Both magnitude and direction are same

• Both magnitude and direction are same