Question

A guitar string is 90 cm long and has a fundamental frequency of 124 Hz. To produce a fundamental frequency, the guitar should be pressed

• A. 60 cm
• B. 30 cm
• C. 20 cm
• D. 10 cm

Answer 1

Answer: (A)

60 cm

Answer 2

Here, $L_{1} = 90cm,\upsilon_{1} = 124Hz$

$\upsilon_{2} = 186Hz$

$L_{2} = \upsilon$

According to the law of length

$\upsilon_{2}L_{2} = \upsilon_{1}L_{1}$

$\therefore L_{2} = \frac{\upsilon_{1}L_{1}}{\upsilon_{2}} = \frac{124 \times 90}{186} = 60cm$