The problem: You wish to impress your friends with your mystical powers and deci

Question

The problem: You wish to impress your friends with your mystical powers and decide to build a small object that you can cause to levitate at the dinner table. How will you do this?

Solution: You decide to place a 0.20-cm high, 1.0-cm long rectangular loop of resistance 0.30-W inside a 2.0-g box. A tiny 1.5-V battery sends a current through the coil (after a hidden switch is turned on). When you place your hands on each side of the box (with a 2.0-T field caused by the magnets hidden between your fingers), the force of the magnetic field causes the top and bottom parts of the current-carrying wire in the loop to rise up into the air, as shown in the illustration.

Mathematical Representation

EFy = 2 I L B = m g

Note that the magnetic force is exerted on the two long horizontal sections of the loop wire. We check to see if the two sides of the equation are equal:

The left side:

2(1.5 V/0.30 W)(1.0 cm)(2.0 T) = 20 N.

The right side:

(2.0 g)(10 m/s2) = 20 N.

(a) Identify any missing elements or errors in the solution.

(b) Provide a corrected solution or missing elements if you find errors

Explanation / Answer

here,

rectangular loop height h=0.2cm

rectangular loop length L=1cm

resistance R=0.3 ohms ( missing letter)

mass of the box m=2g=2*10^-3 kg

magnetic field B=2T

battery potential V=1.5 v

now,

gravtational force, F=m*g

Fg=2*10^-3*9.8

Fg=0.02 N

magnetic force F=i*h*B

F=(v/R)*b*B

F=(1.5/0.3)*1*10^-3*2

Fm=0.02 N

hence Fg=Fm

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