Back to Directory
NEET PHYSICSMedium

If n1,n2n_1, n_2 and n3n_3 are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency nn of the string is given by

A

1n=1n1+1n2+1n3\frac{1}{n}=\frac{1}{n_1}+\frac{1}{n_2}+\frac{1}{n_3}

B

1n=1n1+1n2+1n3\frac{1}{\sqrt{n}}=\frac{1}{\sqrt{n_1}}+\frac{1}{\sqrt{n_2}}+\frac{1}{\sqrt{n_3}}

C

n=n1+n2+n3\sqrt{n}=\sqrt{n_1}+\sqrt{n_2}+\sqrt{n_3}

D

n=n1+n2+n3n=n_1+n_2+n_3

Step-by-Step Solution

  1. Identify the formula for fundamental frequency: The fundamental frequency nn of a stretched string of length ll, tension TT, and linear mass density μ\mu is given by n=12lTμn = \frac{1}{2l}\sqrt{\frac{T}{\mu}} .
  2. Relate length to frequency: Assuming the tension TT and linear mass density μ\mu remain constant for all segments of the string, the length ll is inversely proportional to the frequency nn. Thus, l=Cnl = \frac{C}{n}, where C=12TμC = \frac{1}{2}\sqrt{\frac{T}{\mu}} is a constant.
  3. Use the property of total length: The total length of the string is equal to the sum of the lengths of the individual segments into which it is divided: l=l1+l2+l3l = l_1 + l_2 + l_3
  4. Substitute the length-frequency relationship: Substituting l=Cnl = \frac{C}{n} into the length equation gives: Cn=Cn1+Cn2+Cn3\frac{C}{n} = \frac{C}{n_1} + \frac{C}{n_2} + \frac{C}{n_3} Dividing both sides by the constant CC, we obtain the relationship between the fundamental frequencies: 1n=1n1+1n2+1n3\frac{1}{n} = \frac{1}{n_1} + \frac{1}{n_2} + \frac{1}{n_3}
Practice Mode Available

Master this Topic on Sushrut

Join thousands of students and practice with AI-generated mock tests.

Get Started