1
JEE Main 2016 (Online) 10th April Morning Slot
+4
-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 :
A
$${{{\pi ^2}{r^4}B_0^4} \over {2\tau R}}$$
B
$${{{\pi ^2}{r^4}B_0^2} \over {2\tau R}}$$
C
$${{{\pi ^2}{r^4}B_0^2R} \over \tau }$$
D
$${{{\pi ^2}{r^4}B_0^2} \over {\tau R}}$$
2
JEE Main 2016 (Online) 10th April Morning Slot
+4
-1
Consider an electromagnetic wave propagating in vacuum. Choose the correct statement :
A
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 $$\vec B = {1 \over {\sqrt 2 }}{B_{yz}}{\mkern 1mu} \left( {x,t} \right)\left( {\hat y + \hat z} \right)$$
B
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 $$\vec B = {1 \over {\sqrt 2 }}{B_{yz{\mkern 1mu} }}\left( {y,z,t} \right)\left( {\hat y + \hat z} \right)$$
C
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 $$\vec B = {1 \over {\sqrt 2 }}{B_{yz{\mkern 1mu} }}\left( {x,t} \right)\widehat z$$
D
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 $$\overrightarrow B = {1 \over {\sqrt 2 }}{B_{z{\mkern 1mu} }}\left( {x,t} \right)\widehat y$$
3
JEE Main 2016 (Online) 9th April Morning Slot
+4
-1
Microwave oven acts on the principle of :
A
transferring electrons from lower to higher energy levels in water molecule
B
giving rotational energy to water molecules
C
giving vibrational energy to water molecules
D
giving translational energy to water molecules
4
JEE Main 2016 (Online) 9th April Morning Slot
+4
-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 >> $${L \over R}$$) :
A
B
C
D
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