A square loop made of copper wire is falling out of a region where there is a ma

Question

A square loop made of copper wire is falling out of a region where there is a magnetice field Bext = 0.14 T. The loop is falling with a constant velocity because of the current induced in the loop.

What is the velocity of the loop? Give your answer in m/s to at least three significant digits.

It will be useful to know that:

The mass density of copper (mass per volume) is 9.0x103 kg/m3.

The resistivity of copper is ? = 1.7x10-8 ?-m.

Remember that the resistance of a wire of length L and cross-sectional area A is R = ? L/A.

Explanation / Answer

here,

the magnetic feild , B = 0.14 T

the density , d = 9 * 10^3 kg/m^3

resistivity , p = 1.7 * 10^-8 ohm.m

resistance , r = p*4*L/Area

mass, m = d*A*4*L

let the velocity be v

i = B*v*l /r

i = 1.4 * v * l*area /( p*4*l)

i = 0.35*v*area/p

and the equating the forces

as the loop has zero velocity

f = B*i*L = m*g

1.4 * 0.35 * l*v*area/p = d*area*4*l *g

1.4 * 0.35 * v = (1.7 * 10^-8)*(9 * 10^3)*4*9.8

v = 0.012 m/s

the velocity of loop is 0.012 m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.