The magnitude of current (in mA) through the resistor R₂ in the figure shown is_______.

In the range: 2.79 - 2.81

Concept:

Substitution Theorem states that if an element in a network is replaced by a voltage/current source whose voltage/current at any instant of time is equal to the voltage/current across the element in the previous network then the initial condition in the rest of the network will be unaltered.

Additional Information

Substitution Theorem :

- It is applicable for any linear bilateral network consisting of a number of energy sources with passive elements.
- Any passive element can be substituted in terms of equivalent voltage (or) current and vice versa for further analysis and reduction in the network without disturbing the remaining network.
- Power absorbed by this passive element, and its equivalent substitution voltage / current source remains the same.



Calculation:

Using the substitution theorem, we can replace the current source in parallel to the resistance with a voltage source in series with an equivalent resistance.

For the given circuit, we do the following transformation:





The given circuit is redrawn as:



Applying KVL through the loop, we get:

20 – 2kI – Ik – 4kI + 8 – 3kI = 0

28 = 10 k × I

I = 2.8 mA