Concepts Of Physics MCQ Edition [Volume 1]PhysicsSound Waves
A Kundt's tube apparatus features a copper rod of length 1.0 m clamped at 25 cm from one of its ends. The tube is filled with air having a sound speed of 340 m/s . The powder gathers in heaps separated by a distance of 5.0 cm . Determine the speed of sound waves in copper.
Options
- A6800 m/s
- B3400 m/s
- C4250 m/s
- D1700 m/s
Correct answer
B. 3400 m/s
Step-by-step solution
The distance between the heaps of powder in a Kundt's tube corresponds to the distance between two consecutive nodes in the air column, which is _a 2 . _a 2 = 5.0 cm _a = 10.0 cm = 0.1 m The frequency of the sound wave is given by: f = v_a _a = 340 0.1 = 3400 Hz The copper rod of length 1.0 m is clamped at 25 cm from one end. The clamped point acts as a node and the free ends act as antinodes. The distance from the node to the nearest antinode is _c 4 . _c 4 = 25 cm _c = 100 cm = 1.0 m The speed of sound in the cop