Trial question (1 Viewer)

[jack10]

hey, can someone tell me the answer for this.

this is my working;

F/l=kII/d
F=kIIl/d

F=k(2I)I(2l)/d
F=4kIIl/d
which is 4 times original so I put D, but the answer says C. Is it because only one wire was doubled?

 

[AnimeX]

View attachment 28535

hey, can someone tell me the answer for this.

this is my working;

F/l=kII/d
F=kIIl/d

F=k(2I)I(2l)/d
F=4kIIl/d
which is 4 times original so I put D, but the answer says C. Is it because only one wire was doubled?

Yep, the F/l I think the l refers to the shared length (which is still 1l, not 2l since only one wire is doubled).

 

[jack10]

alright, cool thanks.