Calculating the current in the wire

문제)

A 0.900V potential difference is maintained across a 1.50m length of tungsten wire that has a cross-sectional area of 0.600mm^2. Calculate the current in the wire.

 

 

풀이)

l = 1.50m

A = 0.600mm^2 = 0.600 × 10^-6 m^2 = 6.00 × 10^-7 m^2

△V = 0.900 V

 

V = IR, I = V / R, R = ρ × l ÷ A임을 이용함.

 

tungsten의 ρ(resistivity) = 5.6 × 10^-8

 

I = V / R = ( V × A ) / ( ρ × l )

 

I = ( V × A ) / ( ρ × l ) = ( 0.900 V × 6.00 × 10^-7 m^2 ) / ( 5.6 × 10^-8 × 1.50 m ) = 6.43 A