Q122 / 150 · MHT CET 2019 (Shift 2) · Physics
A stretched wire of length 260 cm is set into vibrations. It is divided into three segments whose frequencies are in the ratio . Their lengths must be
- A80 cm, 60 cm, 120 cm
- Correct answerB120 cm, 80 cm, 60 cm
- C60 cm, 80 cm, 120 cm
- D120 cm, 60 cm, 80 cm
Solution
The frequency produced by a stretched wire is given by
… (i)
Where, p = number of loops formed in vibration,
= length of wire,
T = tension in wire,
and m = mass per unit length of wire
So, form Eq (i), we get
Here, the ratio of frequencies of three segments is
The length of wire, L = 260 cm, so
cm
cm
cm
… (i)
Where, p = number of loops formed in vibration,
= length of wire,
T = tension in wire,
and m = mass per unit length of wire
So, form Eq (i), we get
Here, the ratio of frequencies of three segments is
The length of wire, L = 260 cm, so
cm
cm
cm
Hence, the correct answer is option: 'B'.