JEE Main 2020 (Online) 5th September Evening Slot | Electromagnetic Waves Question 94 | Physics

JEE Main 2020 (Online) 5th September Evening Slot

MCQ (Single Correct Answer)

-1

The correct match between the entries in column I and column II are :

I	II
Radiation	Wavelength
(a) Microwave	(i) 100 m
(b) Gamma rays	(ii) 10^–15 m
(c) A.M. radio waves	(iii) 10^–10 m
(d) X-rays	(iv) 10^–3 m

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

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

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

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

JEE Main 2020 (Online) 5th September Morning Slot

MCQ (Single Correct Answer)

-1

An electron is constrained to move along the y-axis with a speed of 0.1 c (c is the speed of light) in the presence of electromagnetic wave, whose electric field is
$$\overrightarrow E = 30\widehat j\sin \left( {1.5 \times {{10}^7}t - 5 \times {{10}^{ - 2}}x} \right)$$ V/m.
The maximum magnetic force experienced by the electron will be :
(given c = 3 $$ \times $$ 10⁸ ms^–1 and electron charge = 1.6 $$ \times $$ 10^–19 C)

4.8 $$ \times $$ 10^–19 N

2.4 $$ \times $$ 10^–18 N

3.2 $$ \times $$ 10^–18 N

1.6 $$ \times $$ 10^–18 N

JEE Main 2020 (Online) 4th September Evening Slot

MCQ (Single Correct Answer)

-1

The electric field of a plane electromagnetic wave is given by
$$\overrightarrow E = {E_0}\left( {\widehat x + \widehat y} \right)\sin \left( {kz - \omega t} \right)$$
Its magnetic field will be given by :

$${{{E_0}} \over c}\left( {\widehat x + \widehat y} \right)\sin \left( {kz - \omega t} \right)$$

$${{{E_0}} \over c}\left( {\widehat x - \widehat y} \right)\sin \left( {kz - \omega t} \right)$$

$${{{E_0}} \over c}\left( {\widehat x - \widehat y} \right)\cos \left( {kz - \omega t} \right)$$

$${{{E_0}} \over c}\left( { - \widehat x + \widehat y} \right)\sin \left( {kz - \omega t} \right)$$

JEE Main 2020 (Online) 4th September Morning Slot

MCQ (Single Correct Answer)

-1

Choose the correct option relating wave lengths of different parts of electromagnetic wave spectrum:

$$\lambda $$_{radio waves} > $$\lambda $$_{micro waves} > $$\lambda $$_visible > $$\lambda $$_x-rays

$$\lambda $$_visible > $$\lambda $$_x-rays > $$\lambda $$_{radio waves} > $$\lambda $$_{micro waves}

$$\lambda $$_visible < $$\lambda $$_{micro waves} < $$\lambda $$_{radio waves} < $$\lambda $$_x-rays

$$\lambda $$_x-rays < $$\lambda $$_{micro waves} < $$\lambda $$_{radio waves} < $$\lambda $$_visible

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