Each battery shown in the figure has an emf equal to 5 V . Determine the magnetic field B at the point P for any set of values of the resistances.

Step-by-step solution

Let the potential at the bottom-middle junction be 0 V and at the top-middle junction be V . From the polarities of the batteries, the potential at the bottom-left node is 5 V and at the bottom-right node is 5 V . Similarly, the potential at the top-left node is V + 5 V and at the top-right node is V + 5 V . The potential difference across the left resistor is (V + 5) - 5 = V . The potential difference across the middle resistor is V - 0 = V . The potential difference across the right resistor is (V + 5) - 5 = V .