Question

If the wavelength of electromagnetic radiation increases, its energy will:

• A. Increase
• B. Decrease
• C. Remain constant
• D. Become zero

Hint:

Remember: \[ \boxed{ E=\frac{hc}{\lambda} } \] Higher wavelength \(\rightarrow\) Lower energy Lower wavelength \(\rightarrow\) Higher energy.

Answer 1

The Correct Option is B

Concept: The energy of electromagnetic radiation is inversely proportional to its wavelength. It is given by Planck's equation: \[ E=\frac{hc}{\lambda} \] where
• \(E\) = Energy
• \(h\) = Planck's constant
• \(c\) = Speed of light
• \(\lambda\) = Wavelength

Step 1: Observe the relationship. Since \[ E\propto\frac{1}{\lambda}, \] energy decreases as wavelength increases.

Step 2: Choose the correct option. Therefore, \[ \boxed{\text{Energy decreases when wavelength increases}.} \] Hence, the correct option is \[ \boxed{(B).} \]