Two charges of magnitude 5 nC and -2 nC, one placed at points (2 cm, 0, 0) and (x cm, 0, 0) in a region of space, where there is no other external field. If the electrostatic potential energy of the system is -0.5 μ J. The value of x is

Question

Two charges of magnitude 5 nC and -2 nC, one placed at points (2 cm, 0, 0) and (x cm, 0, 0) in a region of space, where there is no other external field. If the electrostatic potential energy of the system is -0.5 μ J. The value of x is (A) 20 cm (B) 80 cm (C) 4 cm (D) 16 cm

Tardigrade Admin · Accepted Answer

Potential energy of system U=(1/4πε0) (q1q2/r) 0.5×10-6=(9×109×5×10-9×(-2)×10-9/(x-2)×10-2) ⇒ x=20 cm

Q. Two charges of magnitude $5 n C$ and $- 2 n C$ , one placed at points $(2 c m, 0, 0)$ and $(x c m, 0, 0)$ in a region of space, where there is no other external field. If the electrostatic potential energy of the system is $- 0.5 μ J$ . The value of $x$ is

$20 c m$

$80 c m$

$4 c m$

$16 c m$

Potential energy of system
$U = \frac{1}{4 π ε _{0}} \frac{q _{1} q _{2}}{r}$
$0.5 \times 1 0^{- 6} = \frac{9 \times 1 0 ^{9} \times 5 \times 1 0 ^{- 9} \times ( - 2 ) \times 1 0 ^{- 9}}{( x - 2 ) \times 1 0 ^{- 2}}$
$\Rightarrow x = 20 c m$

Q. Two charges of magnitude 5nC and −2nC, one placed at points (2cm,0,0) and (xcm,0,0) in a region of space, where there is no other external field. If the electrostatic potential energy of the system is −0.5μJ. The value of x is

20cm

80cm

4cm

16cm