Voltage drop is the loss of electrical voltage while electric current flows through a conductor or component in a circuit. While the current flows through wires or devices, some energy goes to waste because of inherent resistance offered by the material, thus causing a decrease in its voltage by the time it finally reaches its destination. It becomes particularly important in electrical engineering and design due to the excessive voltage drop as it may eventually lead to inefficiencies shorten the lifetime of electrical parts or even damage it. Thus, it is important to know about the voltage drop to design circuits such that circuits deliver ample voltages at all points of the circuit and ensure the correct functionality and safety in applications ranging from household wiring to industrial systems.

Formula 

The voltage drop formula is given as,

V = IZ

Where,

• I = Current in amperes

• Z = impedance in Ω

Solved Problems

Problem 1: A current of 9A flows through a circuit that carries a resistance of 10 Ω. Determine the voltage drop across the circuit.

Solution:

Given,

Current I = 9A,

Impedance Z = 10Ω

the voltage drop formula is given by

V = IZ

V = 9 × 10

V = 90 v.

Problem 2:

Two resistances of 15 Ω and 30 Ω are connected in series. A current of 4 A is introduced through it. Find the voltage drop.

Solution:

Given,

Resistance Z = (15 + 30) Ω

                   Z = 45 Ω,

Current I = 4A

The formula of voltage drop is as under,

V = IZ

   = 4 × 45

V = 180 V