physics Questions

Dimensions of frequency is

Consider the following statements made about the magnification m of an image produced by a convex lens. As the object distance u increases:

(A) From u = 0 to u = f, m increases.

(B) From u = f to u = 2f, m decreases.

(C) From u = 2f to u = ∞, m increases.

Of the above statements:

A simple microscope has a convex lens of focal length 5 cm. If the least distance of distinct vision is 25 cm, the magnification of the microscope in normal adjustment is:

Which of the following phenomenon could not be explained by the wave theory of light?

Which of the following could influence the speed of sound in air?

    (A) Frequency of the sound wave

    (B) Temperature of air

    (C) Humidity of air

Of the thermometers given below, the most suitable thermometer to measure the temperature of a drop of liquid is,

The volume expansivity of a metal is equal to:

When one touches a piece of metal in the environment, one feels it to be colder than a piece of wood. Because,

An ideal transformer has 100 windings in the primary and 200 windings in the secondary. The primary is connected to an A.C. supply of 120 V at 10 A. Then the “voltage/current” in the secondary is:

A radioactive nucleus $_Z^A X$ decays by emission of an α-particle followed by a ϒ-ray. The daughter nucleus thus formed has a mass number and atomic number:

Consider the following statements made regarding an object of mass m at a height h from the surface of the earth.

(A) Gravitational force acting on the object does not depend on h.

(B) Gravitational potential energy of the object does not depend on m.

(C) Gravitational potential energy of the object depends on h.

Of the statements: