a pipe open at both ends resonates to a frequency n1 and a pipe closed at one end resonates to a frequency n2. if they are joined to form a pipe closed at one end , then fundamental frequency will be .......\na) (n1n2)/(2n2+n1)\nb) (2n2n1)/(2n2+n1)\nc) (2n2n1)/n1+n2\nd) (n2+2n1)/n1n2

For open pipe the; fundamental frequency is n₁ = v / 2l₁
l_{1`</sub> = v / 2n<sub>1</sub>
For closed pipe the fundamental frequency is n<sub>2</sub> = v / 4l<sub>2</sub>
l<sub>2`} = v / 4n2
For both pipe is joined and make a closed pipe length will be (l₁ +l₂) then fundamental frequency is n = v / 4(l₁ + l₂ )
by putting value of l₁ and l₂ then we will get n = n₁n₂ / (n₁ + 2n₂)
option a is correct
Thanks &Regards,
Nirmal Singh
Askiitians Faculty