resistance numerical???

Question

a cube is constructed by joining 12 similar wires,each of resistance 6 ohm,current enters at one corner and leaves at diagonally opposite corner of the cube.the equivalent resistance between these two corners will be--
1. 12 ohm
2. 6 ohm
3. 5 ohm
4. 1 ohm

Answer 1

Draw a cube, and label two opposite corners "C1" and "C2". Refer to your figure as you follow this procedure.

Now suppose that a 1A current is sent from C1 to C2. The voltage difference (in volts, between C1 and C2) will then be equal to the equivalent resistance, in ohms:

V = iR = (1A)*R

Next, note that each corner has 3 wires connected to it. So, each wire at C1 will carry 1/3 A of current, as will each wire at C2.

Next, note that each wire leading away from C1 is connected to two wires at the other end. By symmetry, each of those wires will carry half as much current as the first wire, or 1/6 A.

Each of the 1/6 A wires connects to a wire that leads to C2, which we already know carries 1/3 A.

Finally, pick a path (any path) from C1 to C2, which consists of 3 wires. Calculating voltage drops along each wire to get the net voltage between C2 and C1:

V = (1/3 A)*R + (1/6 A)*R + (1/3 A)*R

Divide that V by 1A, and you have the equivalent resistance.

Answer 2

decrease.... much less area for modern to pass by way of skill much less universal resistance. ;) nonetheless does not count, how the question is worded the resistance of any conductor will decrease if the two the radius or length is decreased. till it particularly is a proper conductor devoid of resistance which does no longer exist in nature. i'm an electric powered Engineer ;)

Answer 3

Haven't done Kirkoff circuits in ages, so I guess (1) or (2).