1) Two identical slabs of a given metal are joined together, in two different ways,as shown in figures (a) and (b). What is the ratio of the resistance of these two combinations?

Question

1) Two identical slabs of a given metal are joined together, in two
different ways,as shown in figures (a) and (b) What is the ratio of
the resistance of these two combinations?

Aarushi Mishra · Accepted Answer

Let length of each slab be l and their cross section area be AIn first case they are joint end to endTotal length of this slab combination, l1=l+l=2lcross section area=AResistance of this combination, R1=ρ2lAIn second case they are placed over one anotherTotal length of this slab combination remains same, l2=lcross section area=A+A=2AResistance of this combination, R2=ρl2AR1R2=ρ2lAρl2A=212=4