What are the 3rd, 5th, and 7th harmonics?

Hint: In this question, we need to explain the concept of 3rd, 5th and 7th harmonics. For this, first, we will understand what harmonics is. After that only, we can understand the terms like 3rd, 5th, and 7th harmonics.

Complete step by step solution:
We know that the harmonics are defined as the integral multiples of the fundamental frequency, also known as the main frequency. The fundamental frequencies are multiplied by a positive integer multiple.

Now, we will understand the 3rd, 5th, and 7th harmonics. The third harmonic is now three times the fundamental frequency. It is commonly referred to as the second overtone in a sound instrument such as organ pipes that produce sound by blowing into a pipe.

Similarly, we can say that the fifth and seventh harmonics are five and seven times the fundamental frequency respectively. In simple words, we can say that the third harmonics are 150 hertz if the fundamental frequency is 50 hertz ($3\times 50$ Hz). Likewise, the fifth harmonic is 250 Hz ($5\times 50$Hz) and the seventh harmonic is 350 Hz ($7\times 50$Hz).

Therefore, the nth harmonic is n times the fundamental frequency.

Note: For understanding 3rd, 5th, and 7th harmonics, it is necessary to have an idea regarding the concept of harmonics. Harmonics are the integral multiples of the fundamental frequency in terms of current or voltage. It is important to note that all harmonics are overtones, but not all overtones are harmonics. Overtone refers to every higher standing wave, whereas harmonic refers to instances in which the overtones are integer multiples of the fundamental frequency.