Question

Find the value of resistor r in the given circuit

Answer 1

Answer is option d 6 ohm

Answer 2

Answer:

2 and 8 ohms are in parallel and can be combined, resulting into 2x8/(2+8) = 1.6 ohms.

Similary, 6 and 4 ohms are in parallel, resulting into 6x4/(6+4) = 2.4 ohms.

In total, these 4 res are combined to give 1.6 + 2.4 = 4 ohms.

.

Now, 3, 4 and r are in parallel. so, 4/3= 3 || 4 || r.

On solving them,

3/4 = (1/3) + (1/4) + (1/r)

1/r = (3/4) - (1/4) - (1/3)

1/r = (1/2) - (1/3)

r= 6 ohms.