Question

Diagram shows a thick walled hollow pipe with current flowing in the shaded portion between a and b. Magnetic field in the region between a and b at a distance r from centre will be

• A. Zero
• B. $\frac { \mu _ { 0 } I } { 2 \pi r }$
• C. $\frac { \mu _ { 0 } I } { 2 \pi r }$
• D. $\frac { \mu _ { 0 } I } { 2 \pi r }$

Answer 1

Answer: (C)

$\frac { \mu _ { 0 } I } { 2 \pi r }$

Answer 2

= µ₀Ien B2p r = µ₀Ien ^¾® $\left\{ \begin{array} { c } \pi \left( \mathrm { b } ^ { 2 } - \mathrm { a } ^ { 2 } \right) \ldots \ldots \mathrm { I } \\ \pi \left( \mathrm { r } ^ { 2 } - \mathrm { a } ^ { 2 } \right) \ldots \cdot \frac { \mathrm { I } \left( \mathrm { r } ^ { 2 } - \mathrm { a } ^ { 2 } \right) } { \mathrm { b } ^ { 2 } - \mathrm { a } ^ { 2 } } \end{array} \right\}$

B =