In the circuit shown in Figure the switch S is to be closed. In what direction d
ID: 1598685 • Letter: I
Question
In the circuit shown in Figure the switch S is to be closed. In what direction does the current flow through the resistor PQ? What is the direction of the induced magnetic field?. A current-carrying wire is placed in the external magnetic field B (as shown) What is the magnitude and direction (with respect to the + x axis) of the magnetic force F_mag on the wire if I = 2.5 A, the length of the wire segment immersed in the field is I = 0.7 m, B = 2 T, and the wire makes 55 degree with if = 2.5 A, the length of the wire segment immersed in the field is I = 0.7, B = 2 T, and the wire makes 55 degree with respect to the y - axis? A hair dryer has a power rating of P_ave = 1800 W at 220 V rms in Europe. Assume that the hair drier circuit contains only resistance. A) What is the resistance of the heating element? b) What is the average power by the drier in the US if the rms voltage in the US is 110V?
Explanation / Answer
1) Net volage applied = 5 V so current flows in the anticlockwise direction in coil 1
Using Lenz's law it will flow in the clockwise direction in the second coil to Q to P
2) Use F = ILBsin 90
as direction between current and magnetic field is 90
F = 3.5N
3) P = V^2/R
R = 26.89 ohms
Pus = 450 W