Which one among the following statements is not correct?

• In progressive waves, the amplitude may be constant and neighboring points are out of phase with each other

• In the air or other gases, a progressive antinode occurs at a displacement node and a progressive node occurs at a displacement antinode

• A transverse wave can be polarized while longitudinal
  wave can not be polarized

• A longitudinal wave can be polarized while the transverse wave can not be polarized

A body initially at rest is acted upon by a constant
force. The rate of change of its kinetic energy varies:

• linearly with square root of time

• linearly with time

• linearly with square of time

• inversely with time

A jet plane flies through the air with a velocity of 2 Mach. While the velocity of sound is 332 m/s the airspeed of the plane is:

• 166 m/s

• 66.4 km/s

• 332 m/s

• 664 m/s

Which one among the following statements is correct?

• Convex mirrors are used by doctors to examine oral cavity

• Concave mirrors are used as reflectors

• Convex mirrors are used as reflectors

• Convex mirrors should be used for shaving

Light travels in optical fiber irrespective of its shape because it is a device by which signals can be transferred from one location to another. It is based on the phenomenon of:

• diffraction of light

• refraction of light

• polarization of light

• total internal reflection of light

A man is at rest in the middle of a horizontal plane of a perfectly smooth surface of the ice. He can move himself to the shore by making use of Newton's:

• First law of motion

• Second law of motion

• Third law of motion

• First, second and third laws of motion

Which one among the following is the major cause of blurring and unsharp images of objects observed through a very large telescope at the extreme limit of magnification?

• Air turbulence of earth's atmosphere

• Poor optical polish achievable on large mirrors

• Poor tracking capacities of telescopes

• Varying density of air in the Earth's atmosphere

338.

Bats can ascertain distances, directions, nature, and size of the obstacles at night. This is possible by the reflection of the emitted:

• ultrasonic waves from the bat.

• ultrasonic waves from distant objects.

• supersonic waves from the bat.

• supersonic waves from the distant objects

When a moving bus suddenly applies brakes, the passengers sitting in it fall in the forward direction. This can be explained by:

• the theory of relativity

• Newton's first law

• Newton's second law

• Newton's third law.

The material used for electric fuse is an alloy of tin and lead. This alloy should have:

• high specific resistance and low melting point

• low specific resistance and high melting point

• low specific resistance and low melting point

• high specific resistance and high melting point.