JEE Main 2016 (Online) 10th April Morning Slot | Alternating Current and Electromagnetic Induction Question 188 | Physics

JEE Main 2016 (Online) 10th April Morning Slot

MCQ (Single Correct Answer)

-1

A conducting metal circular-wire-loop of radius r is placed perpendicular to a magnetic field which varies with time as
B = B₀e$${^{{{ - t} \over r}}}$$ , where B₀ and $$\tau $$ are constants, at time t = 0. If the resistance of the loop is R then the heat generated in the loop after a long time (t $$ \to $$ $$\infty $$) is :

$${{{\pi ^2}{r^4}B_0^4} \over {2\tau R}}$$

$${{{\pi ^2}{r^4}B_0^2} \over {2\tau R}}$$

$${{{\pi ^2}{r^4}B_0^2R} \over \tau }$$

$${{{\pi ^2}{r^4}B_0^2} \over {\tau R}}$$

JEE Main 2016 (Online) 10th April Morning Slot

MCQ (Single Correct Answer)

-1

Consider an electromagnetic wave propagating in vacuum. Choose the correct statement :

For an electromagnetic wave propagating in +x direction the electric field is $$\vec E = {1 \over {\sqrt 2 }}{E_{yz}}{\mkern 1mu} \left( {x,t} \right)\left( {\hat y - \hat z} \right)$$

and the magnetic field is $$\vec B = {1 \over {\sqrt 2 }}{B_{yz}}{\mkern 1mu} \left( {x,t} \right)\left( {\hat y + \hat z} \right)$$

For an electromagnetic wave propagating in +x direction the electric field is $$\vec E = {1 \over {\sqrt 2 }}{E_{yz{\mkern 1mu} }}\left( {y,z,t} \right)\left( {\hat y + \hat z} \right)$$

and the magnetic field is $$\vec B = {1 \over {\sqrt 2 }}{B_{yz{\mkern 1mu} }}\left( {y,z,t} \right)\left( {\hat y + \hat z} \right)$$

For an electromagnetic wave propagating in + y direction the electric field is $$\overrightarrow E = {1 \over {\sqrt 2 }}{E_{yz{\mkern 1mu} }}\left( {x,t} \right)\widehat y$$
and the magnetic field is $$\vec B = {1 \over {\sqrt 2 }}{B_{yz{\mkern 1mu} }}\left( {x,t} \right)\widehat z$$

For an electromagnetic wave propagating in + y direction the electric field is $$\overrightarrow E = {1 \over {\sqrt 2 }}{E_{yz{\mkern 1mu} }}\left( {x,t} \right)\widehat z$$
and the magnetic field is $$\overrightarrow B = {1 \over {\sqrt 2 }}{B_{z{\mkern 1mu} }}\left( {x,t} \right)\widehat y$$

JEE Main 2016 (Online) 9th April Morning Slot

MCQ (Single Correct Answer)

-1

Microwave oven acts on the principle of :

transferring electrons from lower to higher energy levels in water molecule

giving rotational energy to water molecules

giving vibrational energy to water molecules

giving translational energy to water molecules

JEE Main 2016 (Online) 9th April Morning Slot

MCQ (Single Correct Answer)

-1

A series LR circuit is connected to a voltage source with
V(t) = V₀ sin$$\Omega $$t. After very large time, current I(t) behaves as
(t₀ >> $${L \over R}$$) :