Question

Consider the following three statements: For any electromagnetic radiation, the product of the wavelength and the frequency is a constant. If a source of light has a wavelength of 3.0 Å, its frequency is 1.0×10¹⁸ Hz. The speed of ultraviolet light is greater than the speed of microwave radiation. Which of these three statements is or are true?(a) Only one statement is true. (b) Statements (i) and (ii) are true. (c) Statements (i) and (iii) are true. (d) Statements (ii) and (iii) are true. (e) All three statements are true.

Answer 1

Answer:

The correct answer is B. Statements (i) and (ii) are true.

Explanation:

Fisrt statement:

Electromagnetic radiation such as wave, wavelength λ and oscillation frequency ν are related by a constant, the speed of light. The equation is given by:

$c= \lambda \nu$

So the first statement is true.

Second statement:

$c=\lambda \nu\\c= 3.0 A \times 1.0\times 10^{18} Hz\\c= 3.0\times 10^{-10} m \times 1.0\times 10^{18} s^{-1}\\c=3\times 10^8 \frac{m}{s}$

The value of c in the vacuum is 3×10⁸ m/s. Hence, the second statement is true.

Third statement:

The speed of any electromagnetic radiation is constant regardless the type of radiation.

Hence, the third statement is false.