JEE Main2017PhysicsWaves and SoundActual
Two wires W 1 and W 2 have the same radius r and respective, densities ρ 1 and ρ 2 , such that ρ 2 = 4 ρ 1 . They are joined together at the point O , as shown in the figure. The combination is used as a sonometer wire and kept under tension T . The point O is midway between the two bridges. When a stationary wave is set up in the composite wire, the joint is found to be a node. The ratio of the n
Options
- A4 : 1
- B1 : 2
- C1 : 1
- D1 : 3
Correct answer
B. 1 : 2
Step-by-step solution
Let p 1 and p 2 be the number of antinodes of both wires. Fundamental frequency remains the same for both wires. n 1 = n 2 T → same r → same l → same n = p 2 l   T π r 2 ρ From the above equation, we have p 1 ρ 1     = p 2 ρ 2     → p 1 p 2 =   ρ 1 ρ 2 The ratio of antinodes is p 1 p 2 = 1 2 .