In the circuit shown in the figure, if potentail at point `A` is taken to be zero, the potential at point `B` is

Options

A. `-2V`
B. `+1V`
C. `-1V`
D. `+2V`

Answer

B

Explanation

Applying Kirchhoff's first law to the point C, we find that a current of 1 A must flow from D to C to get the current of 2 A.
`therefore` The P.D. between D and C i.e. `V_(D)- V_(C )=2 xx 1= 2V`
But it is given that `V_(A)=0 and V_(C )-1 = V_(A)=0`
`therefore V_(C )= 1` V and because `V_(D)- V_(C )= 2V`
`therefore V_(D)=2 +1 =3 and V_(D)-2 = V_(B)`
`therefore 3-2 = V_(B) therefore V_(B)= + 1V`