An infinitely long thin straight wire has uniform charge density of (1/4) × 10-2 cm-1. What is the magnitude of electric field at a distance 20 cm from the axis of the wire ?

Question

An infinitely long thin straight wire has uniform charge density of (1/4) × 10-2 cm-1. What is the magnitude of electric field at a distance 20 cm from the axis of the wire ? (A) 1.12 × 108 NC-1 (B) 4.5 × 108 NC-1 (C) 2.25 × 108 NC-1 (D) 9 × 108 NC-1

Tardigrade Admin · Accepted Answer

We know that E=(λ/2 π ε0 r) =(1/4) × (10-2/10-2) × 18 × 109 × 5 =2.25 × 108 N / C

Q. An infinitely long thin straight wire has uniform charge density of $\frac{1}{4} \times 1 0^{- 2} c m^{- 1} .$ What is the magnitude of electric field at a distance $20 c m$ from the axis of the wire ?

$1.12 \times 1 0^{8} N C^{- 1}$

$4.5 \times 1 0^{8} N C^{- 1}$

$2.25 \times 1 0^{8} N C^{- 1}$

$9 \times 1 0^{8} N C^{- 1}$

We know that
$E = \frac{λ}{2 π ε _{0} r}$
$= \frac{1}{4} \times \frac{1 0 ^{- 2}}{1 0 ^{- 2}} \times 18 \times 1 0^{9} \times 5$
$= 2.25 \times 1 0^{8} N / C$

Q. An infinitely long thin straight wire has uniform charge density of 41​×10−2cm−1. What is the magnitude of electric field at a distance 20cm from the axis of the wire ?

1.12×108NC−1

4.5×108NC−1

2.25×108NC−1

9×108NC−1