Question

The current flowing through \(10 \Omega\) resistor in the circuit shown in the figure is (A) \(50 \mathrm{~mA}\) (B) \(20 \mathrm{~mA}\) (C) \(40 \mathrm{~mA}\) (D) \(80 \mathrm{~mA}\)

Short answer

The current flowing through the 10 Ω resistor in the circuit is approximately 2.76 A. None of the given options (A: 50 mA, B: 20 mA, C: 40 mA, D: 80 mA) match our calculated current, which indicates a potential error in the problem or the options provided.

Step-by-step solution

Analyzing the Circuit

In the given circuit, there are multiple resistors connected in a combination of parallel and series connections. We can start by finding the equivalent resistance of the connected resistors.

Simplifying Parallel Connections

First, we need to simplify the parallel connections in the circuit. There are two parallel connections: 1. 20 Ω and 30 Ω resistors - Let's call their equivalent resistance as R1. 2. 40 Ω and 20 Ω resistors - Let's call their equivalent resistance as R2. Using the formula for equivalent resistance in parallel connections: \(\frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2}\) For R1: \(\frac{1}{R_1} = \frac{1}{20} + \frac{1}{30}\) -> \(R_1 = 12 \Omega\) For R2: \(\frac{1}{R_2} = \frac{1}{40} + \frac{1}{20}\) -> \(R_2 = 13.33 \Omega\)

Calculating the Total Resistance

Now that we have simplified the parallel connections, we can find the total resistance of the circuit by adding all the resistances in series. Total Resistance (Rt) = 10 Ω (given resistor) + R1 + R2 = 10 Ω + 12 Ω + 13.33 Ω = 35.33 Ω

Finding the Total Current Flow

We are given a 200 V battery in the circuit. Using Ohm's law (V = IR), we can find the total current flowing through the circuit: Total Current (It) = \(\frac{V}{R_t}\) = \(\frac{200}{35.33}\) = 5.66 A

Finding the Current across the 10 Ω Resistor

We have the total current flowing through the circuit (It). We need to find the current through the 10 Ω resistor. Since the current splits into two when it reaches the 20 Ω and 30 Ω parallel resistors, we can use the current division rule: Current through 10 Ω resistor (I10) = It × \(\frac{R_1}{R_1 + R_2}\) = 5.66 A × \(\frac{12}{12 + 13.33}\) = 2.76 A We can see that none of the given options match our calculated current. It is crucial to recheck the calculations in this case, and if further calculations also do not yield an answer that matches an option, the student can discuss the discrepancy with the teacher.