An observer is 1.8 m from an isotropic point light source whose power is 250W. Calculate the rms value of the electric and magnetic fields due to the source at the position of the observer.

An observer is at 2 m from an isotropic point source of light emitting 40 W power. What are the rms values of the electric and magnetic fields due to the source at the position of the observer ? [c=3xx10^(8)ms^(-1), epsilon_(0)=8.854xx10^(-12)C^(2)N^(-1)m^(-2)]

Which of the following pair of electric and magnetic fields represents the source of light?

The maximum electric field at a distance of 10m from an isotropic point source of light is 3.0 Vm^(-1) . Calculate (a) the maximum value of magnetic field, (b) average intensity of light at that place and (c ) the power of the source. [c=3xx10^(8)ms^(-1), epsilon_(0)=8.854xx10^(-12)C^(2)N^(-1)m^(-2)]

A beam of light has intensity 2. 8xx 10^(14) W m^(-2) .Calculate the value of amplitude of electric field magnetic field of the beam .

A point source of electromagnetic rediation has an average power output of 960 W. The peak value of the electric field at a distance 400 cm from the source is

In an electromagnetic wave in free space the rms value of the electric field is 3V m^(-1) . The peak value of the magnetic field is

A person is standing at a distance D from an isotropic point source of sound He walks 50.0 m towards the source and observes that the intensity of the sound has doubled. His initial distance D from the source is