Whenever current passes through a resistance of some kind, a voltage drop occurs across that resistance. The amount of the drop is given by Ohm's Law:
V=IR
V = The value of the voltage drop
I = The current through the circuit in amperes
R = The total resistance of the circuit
Let's say you have a simple series circuit containing a 10-volt battery, a 3-ohm resistor, and a 2-ohm resistor in series with each other (if the resisitors are in parallel the voltage drop across the "system" of resistors is equivalent to the input voltage of the system, in this example 10 volts. The current flow through each resistor can then be calculated using Ohm's Law). Ohm's Law tells us that 2 Amps are flowing in the circuit (I = V/R = 10/5 = 2). The voltage drop across the 3-ohm resistor is 6 volts (V = IR = 2*3 = 6).
Do you mean why is the voltage in a circuit lower after the light bulb than before it? If so, it's because the light bulb filament has electrical resistance. When an electrical current flows through a resistance, there is a voltage drop across the resistance (Ohm's law).More fundamentally, the light bulb is producing light, which is a form of energy. The voltage drop across the light bulb comes from the fact that electrical energy is being turned into light. If voltage didn't drop, you would be producing energy from nothing. Furthermore, if there were no voltage drop, your circuit would behave the same whether you had no light bulbs, one light bulb, or eighteen million light bulbs - something that clearly can't be the case.
* resistance increases voltage. Adding more resistance to a circuit will alter the circuit pathway(s) and that change will force a change in voltage, current or both. Adding resistance will affect circuit voltage and current differently depending on whether that resistance is added in series or parallel. (In the question asked, it was not specified.) For a series circuit with one or more resistors, adding resistance in series will reduce total current and will reduce the voltage drop across each existing resistor. (Less current through a resistor means less voltage drop across it.) Total voltage in the circuit will remain the same. (The rule being that the total applied voltage is said to be dropped or felt across the circuit as a whole.) And the sum of the voltage drops in a series circuit is equal to the applied voltage, of course. If resistance is added in parallel to a circuit with one existing circuit resistor, total current in the circuit will increase, and the voltage across the added resistor will be the same as it for the one existing resistor and will be equal to the applied voltage. (The rule being that if only one resistor is in a circuit, hooking another resistor in parallel will have no effect on the voltage drop across or current flow through that single original resistor.) Hooking another resistor across one resistor in a series circuit that has two or more existing resistors will result in an increase in total current in the circuit, an increase in the voltage drop across the other resistors in the circuit, and a decrease in the voltage drop across the resistor across which the newly added resistor has been connected. The newly added resistor will, of course, have the same voltage drop as the resistor across which it is connected.
What happens to the current in a circuit as a capacitor charges depends on the circuit. As a capacitor charges, the voltage drop across it increases. In a typical circuit with a constant voltage source and a resistor charging the capacitor, then the current in the circuit will decrease logarithmically over time as the capacitor charges, with the end result that the current is zero, and the voltage across the capacitor is the same as the voltage source.
emf and voltageAnswerElectromotive force is the potential difference created by a source, such as a battery or generator, when it is not connected to a load -in other words, on 'open circuit'.Voltage drop is the potential difference across a load, such as a resistor, which causes current to flow through that load.A voltage drop occurs, internally, in batteries and generators, when they are supplying a load. The battery or generator's terminal voltage, when supplying a load, is its e.m.f. less its internal voltage drop.
If there is nothing else in the circuit, then the voltage drop across the resistor will be the full supply voltage of 5 volts. The size of the resistor does not matter in this case - it will always be 5 volts.
Voltage drop in an electrical circuit occurs when there is resistance in the circuit, causing a decrease in voltage as the current flows through the components. This drop in voltage is proportional to the amount of resistance in the circuit, following Ohm's Law (V I R).
Resistors reduce voltage in an electrical circuit by impeding the flow of electric current, which causes a drop in voltage across the resistor. This drop in voltage is proportional to the amount of resistance in the circuit.
A voltage drop in an electrical circuit is caused by resistance in the circuit components, such as wires, resistors, or other devices. This resistance reduces the flow of current and results in a decrease in voltage across the circuit.
Resistors drop voltage in an electrical circuit by impeding the flow of current, causing a voltage drop across the resistor according to Ohm's Law (V I R). This results in a decrease in voltage across the resistor, allowing for control and regulation of the electrical current in the circuit.
Voltage drop in electrical circuits is caused by the resistance in the wires and components of the circuit. When current flows through a circuit, some of the electrical energy is converted into heat due to this resistance, leading to a decrease in voltage along the circuit.
Resistors lower voltage in an electrical circuit by impeding the flow of electric current, which causes a drop in voltage across the resistor. This drop in voltage helps regulate the overall voltage in the circuit and control the amount of current flowing through it.
Voltage drop in electrical circuits is caused by the resistance in the circuit components, such as wires, connections, and devices, which leads to a decrease in voltage as current flows through them.
When a current flow on a conductor , or load or resistor, some voltage will drop across that load or resistor.AnswerA voltage drop is the potential difference appearing across individual components in a circuit, necessary to drive current through those components. The sum of the individual voltage drops around a series circuit will equal the supply voltage applied to that circuit.
A resistor limits current in an electrical circuit by impeding the flow of electrons, which reduces the amount of current passing through it. This, in turn, helps regulate the voltage in the circuit by creating a drop in voltage across the resistor.
Voltage drop is typically measured in units of volts (V). It is a way to quantify the loss of voltage as electrical current flows through a circuit due to resistance. Voltage drop can be calculated by measuring the difference in voltage between two points in the circuit.
Voltage x current. In a resistor for example it is the voltage drop across it that is relevant, it may be part of a circuit.
Voltage drop in electrical circuits can be caused by factors such as resistance in wires, connections, and components, as well as the length and thickness of the wires. These factors can lead to a decrease in voltage as electricity flows through the circuit.