1
JEE Main 2020 (Online) 7th January Morning Slot
+4
-1
If the magnetic field in a plane electromagnetic wave is given by
$$\overrightarrow B$$ = 3 $$\times$$ 10-8 sin(1.6 $$\times$$ 103x + 48 $$\times$$ 1010t)$$\widehat j$$ T, then what will be expression for electric field ?
A
$$\overrightarrow E$$ = (9sin(1.6 $$\times$$ 103x + 48 $$\times$$ 1010t)$$\widehat k$$ V/m)
B
$$\overrightarrow E$$ = (60sin(1.6 $$\times$$ 103x + 48 $$\times$$ 1010t)$$\widehat k$$ V/m)
C
$$\overrightarrow E$$ = (3 $$\times$$ 10-8 sin(1.6 $$\times$$ 103x + 48 $$\times$$ 1010t)$$\widehat i$$ V/m)
D
$$\overrightarrow E$$ = (3 $$\times$$ 10-8 sin(1.6 $$\times$$ 103x + 48 $$\times$$ 1010t)$$\widehat j$$ V/m)
2
JEE Main 2019 (Online) 12th April Evening Slot
+4
-1
A plane electromagnetic wave having a frequency v = 23.9 GHz propagates along the positive z-direction in free space. The peak value of the Electric Field is 60 V/m. Which among the following is the acceptable magnetic field component in the electromagnetic wave ?
A
$$\overrightarrow B$$ = 2 × 10–7 sin(1.5 × 102 x + 0.5 × 1011t) $$\widehat j$$
B
$$\overrightarrow B$$ = 60 sin(0.5 × 103x + 0.5 × 1011t) $$\widehat k$$
C
$$\overrightarrow B$$ = 2 × 10–7 sin(0.5 × 103 z + 1.5 × 1011t) $$\widehat i$$
D
$$\overrightarrow B$$ = 2 × 10–7 sin(0.5 × 103 z - 1.5 × 1011t) $$\widehat i$$
3
JEE Main 2019 (Online) 12th April Morning Slot
+4
-1
An electromagnetic wave is represented by the electric field $$\overrightarrow E = {E_0}\widehat n\sin \left[ {\omega t + \left( {6y - 8z} \right)} \right]$$ . Taking unit vectors in x, y and z directions to be $$\widehat i,\widehat j,\widehat k$$ , the direction of propagation $$\widehat s$$, is :
A
$$\widehat s = {{3\widehat i - 4\widehat j} \over 5}$$
B
$$\widehat s = {{ - 4\widehat k + 3\widehat j} \over 5}$$
C
$$\widehat s = \left( {{{ - 3\widehat j + 4\widehat k} \over 5}} \right)$$
D
$$\widehat s = {{4\widehat j - 3\widehat k} \over 5}$$
4
JEE Main 2019 (Online) 10th April Evening Slot
+4
-1
Light is incident normally on a completely absorbing surface with an energy flux of 25 W cm–2. If the surface has an area of 25 cm2, the momentum transferred to the surface in 40 min time duration will be :
A
6.3 × 10–4 Ns
B
5.0 × 10–3 Ns
C
1.4 × 10–6 Ns
D
3.5 × 10–6 Ns
EXAM MAP
Medical
NEET