If a sinusoidal electromagnetic wave with intensity 18 w/m2 has an electric field of amplitude e, then a 36 w/m2 wave of the same wavelength will have an electric field of amplitude if a sinusoidal electromagnetic wave with intensity 18 has an electric field of amplitude , then a 36 wave of the same wavelength will have an electric field of amplitude (a) 4e (b) 22√e(c) 2e(d) 2√e.

√2 E

Explanation:

In an electromagnetic wave, the amplitude defines the energy a wave carries. That energy is carried along through fields which means larger the strength of the field, more work can it do on the charges in the field. This signifies that the wave carries more energy.

The wave energy is proportional to the square of its amplitude( )

Given 18 ∝

So, for 36, we multiply both sides with two

36 ∝

36W/m2 will have amplitude √2 E

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.