JEE · Physics · Electromagnetic Waves doubts
8 doubts found
Why can radio waves and X-rays travel at the same speed but behave so differently?
In vacuum both are electromagnetic waves, so Maxwell's equations give the same speed c.
What does “Changing fields sustain an electromagnetic wave” actually mean in Electromagnetic Waves, and why does it matter for JEE?
A changing electric field produces magnetic effects and a changing magnetic field produces an electric field. This coupled disturbance can travel through vacuum without charges continuously carrying it forward.
I keep getting “Changing fields sustain an electromagnetic wave” questions wrong in Electromagnetic Waves. What's the trap?
saying electromagnetic waves require a material medium.
What does “Transverse nature” actually mean in Electromagnetic Waves, and why does it matter for JEE?
In a plane electromagnetic wave, electric field E and magnetic field B are perpendicular to each other and to the direction of propagation. Their cross-product direction E x B points along energy flow.
I keep getting “Transverse nature” questions wrong in Electromagnetic Waves. What's the trap?
drawing E or B along the direction of travel.
What does “Speed and field ratio” actually mean in Electromagnetic Waves, and why does it matter for JEE?
In vacuum all electromagnetic frequencies travel at c. For a plane wave E_0/B_0 = c; frequency changes photon energy and wavelength, not vacuum speed.
I keep getting “Speed and field ratio” questions wrong in Electromagnetic Waves. What's the trap?
claiming gamma rays travel faster than radio waves in vacuum.
What does “Electromagnetic spectrum” actually mean in Electromagnetic Waves, and why does it matter for JEE?
Radio, microwave, infrared, visible, ultraviolet, X-ray and gamma radiation are the same kind of wave ordered by increasing frequency. Higher frequency means shorter wavelength and greater photon energy.