Match List - I with List - II. List-I List-II (a) Source of microwave frequency (i) Radioactive decay of nucleus (b) Source of infrared frequency (ii) Magnetron (c) Source of Gamma Rays (iii) Inner shell electrons (d) Source of X -rays (iv) Vibration of atoms and molecules (v) LASER (vi) RC circuit Choose the correct answer from the options given below:

(a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)

(a)-(ii), (b)-(iv), (c)-(vi), (d)-(iii)

(a)-(vi), (b)-(iv), (c)-(i), (d)-(v)

(a)-(vi), (b)-(v), (c)-(i), (d)-(iv)

MEDIUM

Earn 100

What is the correct formula to calculate the gaining ratio?

50% studentsanswered this correctly

Important Questions on Electromagnetic Waves

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Find the rate of change of the area of a circle with respect to its radius $r$ when $r = 3 c m$

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

2

m ladder leans against a vertical wall. If the top of the ladder begins to slide down the wall at the rate

25 c m / s e c

, then the rate (in cm/sec.) at which the bottom of the ladder slides away from the wall on the horizontal ground when the top of the ladder is

1

m above the ground is:

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

The radius of a circle is increasing at the uniform rate of

3 cm / sec

. At the instant when the radius of the circle is

2 cm

, its area increases at the rate of

k π

{cm}^{2}

, then

k =

_____

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

A stone is dropped into a quiet lake and waves move in circles at a speed of

4

cm per second. At the instant when the radius of the circular wave is

10

cm, how fast is the enclosed area increasing?

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Long distance short- wave radio broadcasting uses

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

The total revenue in Rupees received from the sale of '

x

' units of a product is given by

R (x) = 3 x^{2} + 36 x + 5

. The marginal revenue, when

x = 15

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

The total cost

C (x)

associated with the production of

x

units of an item is given by

C (x) = 0 \cdot 005 x^{3} - 0 \cdot 02 x^{2} + 30 x + 5000

. Find the marginal cost when

3

units are produced, where by marginal cost we mean the instantaneous rate of change of total cost at any level of output.

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Find the rate of change of the area of a circle with respect to its radius

r

r = 6 cm .

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Equation for wave vector is:

HARD

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

A water tank has the shape of an inverted right circular cone, whose semi-vertical angle is

{t a n}^{- 1} (\frac{1}{2}) .

Water is poured into it at a constant rate of

5 cubic m / \min .

Then the rate

(

m / \min),

at which the level of water is rising at the instant when the depth of water in the tank is

10 m;

is:

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

A spherical iron ball of radius

10 c m

is coated with a layer of ice of uniform thickness that melts at a rate of

50 c m^{3} / m i n .

When the thickness of the ice is

5 c m,

then the rate at which the thickness

(

c m / m i n)

of the ice decreases, is :

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Match List - I with List - II.

List-I		List-II
(a)	Source of microwave frequency	(i)	Radioactive decay of nucleus
(b)	Source of infrared frequency	(ii)	Magnetron
(c)	Source of Gamma Rays	(iii)	Inner shell electrons
(d)	Source of $X$ -rays	(iv)	Vibration of atoms and molecules
		(v)	LASER
		(vi)	RC circuit

Choose the correct answer from the options given below:

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

The source of electromagnetic wave can be a charge.

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Out of the following options which one can be used to produce a propagating electromagnetic wave?

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

A magnetic field can be produced by

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Can we produce a pure electric or magnetic wave in space? Why?

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Discuss the source of electromagnetic waves.

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

A non-monochromatic light is used in an experiment on photoelectric effect. The stopping potential

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

The source of electromagnetic waves can be a charge.

EASY

Physics>Modern Physics>Electromagnetic Waves>Sources of Electromagnetic Waves

Suppose that the electric field part of an electro-magnetic wave in vacuum is

\vec{E} = 3.1 \cos [(1.8 y) + (5.4 \times 10^{8} t)] \hat{i}

. What is the direction of propagation?

What is the correct formula to calculate the gaining ratio?

Important Questions on Electromagnetic Waves

Learn and Prepare for any exam you want !