Question

A 10 ohm and a 15-ohm resistor are connected in parallels to a 12 V battery. Find the following:

a. The total resistance.

b. The total current in the circuit.

c. The total power supplied by the battery.

d. Find the resistance of copper wire with a diameter of 4E-3 m and a length of 50 m. The resistivity at 20 0C is 1.68E-8 ohm-m.

e. Two parallel, long wires are separated by 0.50 m. Wire 1 carries a current of 15 A up and wire 2 carries a current of 10 A down. Find the magnitude of the force per unit length on the wires.

USE UNITS/ SUB UNITS AND SHOW ALL WORK

Answer 1

R1= 10 Ohm, R2= 15 Ohm resistors are in parallel.

Thus, the equivalent resistance,

a) Total resistance, R= 6 Ohm.

b) Total current,

I=V/R=12/6= 2 Amperes.

c) Power supplied by the battery,

P= V*I = 12*2 = 24 Watts.

d) Diameter, d= 4*10^-3m

Radius, r= 2*10^-3m

So, cross-sectional area,

Length, l= 50m

Resistivity,

So, the resistance,