Question

The current flowing through the 3: resistor in the electric circuit shown below is 3 × Z x 10–2

A. The value of Z is?
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Answer 1

Answer:

30

Explanation:

first let's consider the resistance of the entire circuit it's going to be 1+ 12*4/(12 +4) + 6 = 10 Ω

next we will find out the current in the entire circuit = 12/10 = 1.2 A

so the voltage after 1Ω resistor will be 1.2 V --- V1

and that after the parallel resistors will be 1 + 12*4/(12 +4) => 4*1.2 = 4.8 ---- V2

so now we know that V2 - V1 = I1 * 12 = i2 * 4

now 3.6 = i2 * 4

i2 = 0.9

so voltage before 3 Ω is 0.9V and after it is 3.6 V

this means there is a voltage difference of 2.7

so the current through 3 Ω is 0.9 A

Now,

$0.9 = 3 \times z \times {10}^{ - 2} \\ 0.9 \times 100 \div 3 = 30 = z$