Two charges of magnitude 4 × 10-3 C and 6 × 10-8 C at A and B are 50 cm apart. The electric potential is zero at a point along A B, where distance from A is given by

Question

Two charges of magnitude 4 × 10-3 C and 6 × 10-8 C at A and B are 50 cm apart. The electric potential is zero at a point along A B, where distance from A is given by (A) 40 cm (B) 20 cm (C) 10 cm (D) 30 cm

Tardigrade Admin · Accepted Answer

Suppose, potential at point P is zero. V1=V2 K × (4 × 10-8/r1)=K × (6 × 10-8/r2) (4 × 10-8/x)=(6 × 10-8/(50-x)) 4(50-x)=6 x 200-4 x=6 x ⇒ 10 x=200 x=20 cm

Q. Two charges of magnitude $4 \times 1 0^{- 3} C$ and $6 \times 1 0^{- 8} C$ at $A$ and $B$ are $50 c m$ apart. The electric potential is zero at a point along $A B$ , where distance from $A$ is given by

40 cm

20 cm

10 cm

30 cm

Suppose, potential at point $P$ is zero. $V_{1} = V_{2}$
$K \times \frac{4 \times 1 0 ^{- 8}}{r _{1}} = K \times \frac{6 \times 1 0 ^{- 8}}{r _{2}}$
$\frac{4 \times 1 0 ^{- 8}}{x} = \frac{6 \times 1 0 ^{- 8}}{( 50 - x )}$
$4 (50 - x) = 6 x$
$200 - 4 x = 6 x$
$\Rightarrow 10 x = 200 x = 20 c m$

Q. Two charges of magnitude 4×10−3C and 6×10−8C at A and B are 50cm apart. The electric potential is zero at a point along AB, where distance from A is given by