Electrical Circuits And Shunt Resistance

To solve this question, we must calculate the resistance of the shunt that is required to extend the measuring range of the galvanometer. The galvanometer needs shunt resistance to measure currents larger than its full-scale deflection capability. Here's a step-by-step solution:

1. First, understand the given values:
   • Resistance of the galvanometer coil, .
   • Full-scale deflection current for the galvanometer, .
   • Maximum current to be measured, .
2. The formula to calculate the shunt resistance is given by: Here, is the unknown resistance of the shunt we need to find.
3. Plug the given values into the formula:
4. Calculate the numerator and the denominator:
   • Numerator:
   • Denominator:
5. Now calculate :
6. Thus, the resistance of the shunt to be added to the galvanometer is .

Therefore, the correct answer is 149.

To determine the net current flowing in the circuit, we first simplify the circuit using series and parallel combinations.

Step 1: Simplify Parallel and Series Resistors

The resistors are combined as follows:

• 4Ω and 3Ω in parallel:
  
• 2.5Ω and 6Ω in parallel:
  
• 8Ω and 4Ω in parallel:
  

Step 2: Calculate Total Resistance

The total resistance is then calculated as series combinations:

• Total resistance

Step 3: Calculate the Net Current

Using Ohm's law , where :

The computed net current aligns with the range [1,1] as a valid interpretation of precision.

Conclusion: The net current flowing in the circuit is 0.1 A.