Question

What current density is required to provide a pressure difference of 1 atm between any two points if $B=2.2T$ and $l=35mm$

• A. $1.4\times {10}^{3}A{m}^{-2}$
• B. $7.2\times {10}^{6}A{m}^{-2}$
• C. $1.3\times {10}^{5}A{m}^{-2}$
• D. $1.3\times {10}^{6}A{m}^{-2}$

Answer 1

The correct option is D $1.3\times {10}^{6}A{m}^{-2}$

Magnetic force due to uniform magnetic field $F=BIl$
Now current density $J=\frac{I}{A}$
Pressure due to this uniform field=$\frac{F}{A}=\frac{BIl}{A}=BJl$
$J=\frac{\Delta p}{Bl}=\frac{{10}^5}{2.2\times 35\times {10}^{-3}}=1.3\times {10}^{6}A{m}^{-2}$