0

Guest

Courses New

A stretched wire of 60 cm vibrates with a fundamental note of frequency 256 Hz. If the length of the wire is decreased to 15 cm while the tension in kept constant. The fundamental frequency of the wire will be (a) 64 Hz (b) 256 Hz (c) 512 Hz (d) 1024 Hz

A stretched wire of 60 cm vibrates with a fundamental note of frequency 256 Hz. If the length of the wire is decreased to 15 cm while the tension in kept constant. The fundamental frequency of the wire will be

(a) 64 Hz
(b) 256 Hz
(c) 512 Hz
(d) 1024 Hz

Grade:Upto college level

2 Answers

Arun
25750 Points
3 years ago
Frequency of fundamental note is given by 
Here, ν is the frequency of fundamental note , v is speed of wave , l is the length of string , T is tension in the string and μ is mass density { mass per unit length}
in first case , 
---(1)
in second case, 
----(2)
From equations (1) and (2) 
256/320 = 2(l-10)/2l 
⇒ 4/5 = ( l - 10)/l 
⇒ 4l = 5( l - 10) 
⇒ 4l = 5l - 50 ⇒ l = 50 cm 
Hence, length of string is 50 cm
 
Vikas TU
14149 Points
3 years ago
Dear student 
The above ans is not properly written 
Frequency of fundamental note is given by
Here, ν is the frequency of fundamental note , v is speed of wave , l is the length of string , T is tension in the string and μ is mass density { mass per unit length}
in first case ,
256 = v/21 sqrt(T/mew)---(1)
in second case,
320 = v/2(1-10) sqrt(T/mew)----(2)
From equations (1) and (2)
256/320 = 2(l-10)/2l
⇒ 4/5 = ( l - 10)/l
⇒ 4l = 5( l - 10)
⇒ 4l = 5l - 50 ⇒ l = 50 cm
Hence, length of string is 50 cm

Think You Can Provide A Better Answer ?

Other Related Questions on Engineering Entrance Exams

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More