First harmonic question ( from Aqa paper)

[bonbon22]

Homework Statement

https://filestore.aqa.org.uk/sample-papers-and-mark-schemes/2016/june/AQA-74072-QP-JUN16.PDF

it is the multiple choice question number 13

Relevant Equations

first harmonic equation

The answer is f/square root 2

If F = 1/2l * square root ( Tension/ mass per unit length )
---------> this becomes I am assuming 1/2l * square root ( length * Tension/ mass )
this would give an answer of F

yet the answer is F/ square root (2)

 

[TSny]

Does anything happen to the mass $m$ when the length of the wire is doubled?

 

[bonbon22]

Does anything happen to the mass $m$ when the length of the wire is doubled?

ahhh i see ... cheers