Question

Derive an expression for the equivalent resistance in series and parallel.
-3 mark question.
Thanks​

Answer 1

The amount of water it displaces (shaded area) weighs as much as the ship. The weight of the ship pulling down (red arrow) and the upthrust pushing up (blue arrow) are equal and opposite forces, so the ship floats. ... Now the weight of the ship is more than the maximum possible upthrust so it sinks to the bottom

Answer 2

Let resistances be r1 and r2

In series connection current is the same.voltage differs.

Total.voltage=v1+v2

We know that V=IR

IR=IR1+IR2

Taking current common we get Rs=R1+R2

For parallel resistance:

V will be same

I=V/R

I=I1+I2

V/R=V/R1+V/R2

1/R=1/R1+1/R2