MHTCET 2016 Physics Solved Paper

(c) The velocity of wave travelling on string (v) is given by
v=nλ=

λ

2L

√

T

μ

(∵n=

1

2L

√

T

μ

)
Here, µ = mass per unit length
∴ v=√

T

m∕l

⇒ v=√

Tl

m

Young’s modulus (Y) is given by,
Y =

T×l

AΔL

∴ T × l = YA Δ L
∴ V ∝ √A (A= Area)
The radius of the string A is 2r and string B is r.
∴

vA

vB

=√

4r2

r2

= √4 = 2
[ ∵ Y is same for both the strings.]