Pls explain how they chose the loop here and what to do in these kind of questions like how to choose loop in these questions?

Solution:

A node refers to a junction connecting two or more current-carrying routes like cables and other components. Kirchhoff’s current law can also be applied to analyse parallel circuits.
The voltage around a loop equals the sum of every voltage drop in the same loop for any closed network and equals zero.

When you begin at any point of the loop and continue in the same direction, note the voltage drops in all the negative or positive directions and returns to the same point. It is essential to maintain the direction either counterclockwise or clockwise; otherwise, the final voltage value will not be zero.

1. Following are the things that you should keep in mind while approaching the problem:​​​​​​
2. You need to choose the direction of the current. In this problem, let us choose the clockwise direction.When the current flows acro
3. ss the resistor, there is a potential decrease. Hence, V = IR is signed negative.
4. If the current moves from low to high, then the emf (E) source is signed positive because of the energy charging at the emf source. Likewise, if the current moves from high to low voltage (+ to -), then the source of emf (E) is signed negative because of the emptying of energy at the emf source.