Answer:
"h" signifies Planck's constant
Explanation:
In the equation energy E = h X v
The "h" there signifies Planck's constant
Planck's constant is a value, that shows the rate at which the energy of a photon increases/decreases, as the frequency of its electromagnetic wave changes.
It was named after Max Planck who discovered this unique relationship between the energy of a light wave and its frequency.
Planck's constant, "h" is usually expressed in Joules second
Planck's constant = 
Speed is different from velocity. Velocity is a vector quantity and has a direction. Speed is a scalar quantity and does not require a direction. The answer must be D).
Answer:
Explanation:
a ) Direction of the magnetic field will be in positive x direction.
The direction of the vector E X B gives the direction of motion of wave.
b ) Magnitude of magnetic field is given by the relation
E₀ / B₀ = c , c is velocity of light
B₀ = E₀ / c
= 20 / (3 x 10⁸)
= 6.67 x 10⁻⁸ T
c ) Average power flowing per unit area by this wave is called Poynting vector
c ε₀E₀² , ε₀ = 8.85X10⁻¹²
= 3 X 10⁸ X 8.85 X 10⁻¹² X 20²
= 1.062 W m⁻²
They exhibit identical behaviors with regard to changes of phase.
If there is any difference, it is too small to be measured, and none
has been observed.