1
JEE Main 2022 (Online) 28th June Evening Shift
+4
-1 An EM wave propagating in x-direction has a wavelength of 8 mm. The electric field vibrating y-direction has maximum magnitude of 60 Vm$$-$$1. Choose the correct equations for electric and magnetic fields if the EM wave is propagating in vacuum :

A

$${E_y} = 60\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat j\,\,V{m^{ - 1}}$$

$${B_z} = 2\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat k\,\,T$$

B

$${E_y} = 60\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat j\,\,V{m^{ - 1}}$$

$${B_z} = 2 \times {10^{ - 7}}\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat k\,\,T$$

C

$${E_y} = 2 \times {10^{ - 7}}\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat j\,\,V{m^{ - 1}}$$

$${B_z} = 60\sin \left[ {{\pi \over 4} \times {{10}^3}(x - 3 \times {{10}^8}t)} \right]\widehat k\,\,T$$

D

$${E_y} = 2 \times {10^{ - 7}}\sin \left[ {{\pi \over 4} \times {{10}^4}(x - 4 \times {{10}^8}t)} \right]\widehat j\,\,V{m^{ - 1}}$$

$${B_z} = 60\sin \left[ {{\pi \over 4} \times {{10}^4}(x - 4 \times {{10}^8}t)} \right]\widehat k\,\,T$$

2
JEE Main 2022 (Online) 27th June Evening Shift
+4
-1 If L, C and R are the self inductance, capacitance and resistance respectively, which of the following does not have the dimension of time?

A
RC
B
$${L \over R}$$
C
$$\sqrt{LC}$$
D
$${L \over C}$$
3
JEE Main 2022 (Online) 27th June Evening Shift
+4
-1 Given below are two statements :

Statement I : A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.

Statement II : In a material medium, the EM wave travels with speed $$v = {1 \over {\sqrt {{\mu _0}{ \in _0}} }}$$. In the light of the above statements, choose the correct answer from the options given below.

A
Both Statement I and Statement II are true
B
Both Statement I and Statement II are false
C
Statement I is correct but Statement II is false
D
Statement I is incorrect but Statement II is true
4
JEE Main 2022 (Online) 27th June Morning Shift
+4
-1 The current flowing through an ac circuit is given by

I = 5 sin(120$$\pi$$t)A

How long will the current take to reach the peak value starting from zero?

A
$${1 \over {60}}$$ s
B
60 s
C
$${1 \over {120}}$$ s
D
$${1 \over {240}}$$ s
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination