The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is:

Explanation

The long wavelength limit of a series corresponds to the transition from the next highest energy level to the base level of the series. For the Lyman series, this is the transition from n=2 to n=1, resulting in a frequency calculation based on the formula: f = R_H(1/n_1^2 - 1/n_2^2). For Lyman, substituting n_1 = 1 and n_2 = 2 gives: f_Lyman ∝ 1/1^2 - 1/2^2 = 3/4. For the Balmer series, the transition is from n=3 to n=2, resulting in: f_Balmer ∝ 1/2^2 - 1/3^2 = 5/36. Therefore, the ratio of the frequencies is calculated as follows: (3/4)/(5/36) = 27/5. Hence, the correct answer is Option A (27:5).Options B, C, and D incorrectly represent the frequency calculations and ratios, leading to incorrect conclusions.