10 The tension of a stretched string is increased by 69% In order to keep its frequency of vibration constant, - Physics - Electromagnetic Waves

Question

10 The tension of a stretched string is increased by 69% In order
to keep its frequency of vibration constant, its length must be
increased by ---

Vara · Accepted Answer

The expression for frequency of vibration in a stretched string
is,

n=12LTμHere, L is length of the string          T is tension          μ is mass per unit length

n αTLFor constant frequency,TL=constantL α TL2L1=T2T1Let T1=100 and L1=100then T2=100 + 69 = 169Hence,L2100=169100L2100=1310L2=130Percentage increase in length for constant frequency:L2-L1=130-100               =30%

10.The tension of a stretched string is increased by 69%.In order to keep its frequency of vibration constant, its length must be increased by ---