Different Circuit Conditions

Closed-loop or route electric circuits form a network of electrical components through which electrons can flow. This walkway is created with electrical lines and is powered by a battery. Electrons start to flow at the source and exit the electrical circuit at a point known as the return. Only one closed loop from the positive to the negative end completes an electrical circuit. This is the most basic type of electric circuit; the circuit found inside a television is more intricate and has additional components.

Electric Circuit Symbols

A symbol can be found on every component and product in an electric circuit. In a circuit diagram, symbols represent circuit components. The basic symbols that appear in a circuit diagram are presented below.

Simple Circuit

A basic circuit consists of a switch, a power source, conductors and load.

• The power source is the cell.

• The resistor is also known as the load. When the circuit is turned on, it turns on a light bulb.

• Copper wires with no insulation serve as conductors. The load is connected to the power source on one end of the cable and the power source is connected to the load on the other.

• A switch is a device that allows you to open or close a circuit. A small gap in the circuit acts as a switch. Switches come in several shapes and sizes. 

Different Circuit Conditions

Open circuit condition

When no current flows via a circuit, it is said to be open. This could occur if the key is not plugged in, if any of its components are not made of metal or if the circuit is broken.

The circuit current (I)  = 0

Closed circuit condition:

When every portion of a circuit is formed of a conductor and current flows through it when the key is inserted or the circuit is complete, it is said to be closed.

The current provided by the cell I= E / R+r,

Where E is the potential of battery,

R is the resistance

r is the internal resistance of the battery.

V = iR gives the potential difference (PD) across the resistance.

Potential drop inside the cell = ir.

Equation of cell, E = V + ir (E > V).

The cell’s internal resistance (r) is given by,

r = [ E – V ]/i.

The external resistance (R) dissipated power (P) is given by:

P = V * I

Short circuit condition:

A short circuit is an unusual connection between two nodes of an electrical circuit intended to be of different voltages.

The Potential difference (V) is = 0

Current in an short circuit = E / r

Problems on Circuit Conditions:

Problem 1: 

Consider an electric iron with a resistance of 50 ohms and a current of 3.2 A flowing through it. Determine the voltage difference between the two locations.

Solution: 

If we are asked to compute the value of voltage given the current and resistance values, we are down to I and R or more specifically, I R.

As a result, we determine the value of V using this formula:

V = I R 

We get by substituting the numbers in the equation.

V = 3.2 * 50 = 160 V 

V = 160 volts

Problem 2: 

A fully resistive electrical equipment is connected to an EMF source of 8.0 V. (a light bulb). It is powered by a 2.0 A electric current. Assume that the conducting wires have no resistance. Determine how much resistance the electrical appliance provides.

Solution:

When asked to calculate the value of resistance given the voltage and current values, we are only left with V and I, specifically V / I. 

By substituting the numbers in the equation, we get

R = V / I 

R = 8 V / 2 A = 4 

R = 4 ohm

Conclusion:

Electric current only flows in the presence of a continuous connection from a battery to various components and back. Any disruption causes the current to stop flowing.

Electric batteries must be handled carefully and their two terminals should never be connected in the absence of a bulb or a load. This is because the chemicals inside react very rapidly, generating a high volume of energy that can result in an explosion.