Question

The tension in a piano wire is 10N. What should be the tension in the wire to produce a note of double the frequency

• A. 5 N
• B. 20 N
• C. 40 N
• D. 80 N

Answer 1

Answer: (C)

40 N

Answer 2

$n \propto \sqrt{T}$⇒ $\frac{n_{1}}{n_{2}} = \sqrt{\frac{T_{1}}{T_{2}}}$ ⇒ $\frac{n}{2n} = \sqrt{\frac{10}{T_{2}}}$⇒ $T_{2} = 40N$