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How does current change across a resistor?
Current changes across a resistor in direct proportion to the voltage applied. This relationship is described by Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R), or I V/R.
If the resistance in the circuit is increased what will happen to the current and voltage?
* 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.
Why do resistor voltage decrease while capacitor discharges?
The reason why resistor voltage decreases while a capacitor discharges is because the resistor acts like a source of electrical energy. As the capacitor discharges, it draws energy from the resistor, which causes the voltage across the resistor to decrease. This is because the capacitor is acting like a drain, and is taking energy out of the resistor, thus causing the voltage across the resistor to decrease. The resistor and capacitor work together in order to create a discharge circuit. This is done by connecting the capacitor to the resistor, and then to a voltage source. The voltage source supplies the energy to the resistor, and then the resistor transfers this energy to the capacitor. As the capacitor discharges, it takes energy from the resistor, which causes the voltage across the resistor to decrease. In order to understand this process better, it is important to understand the basics of Ohm's Law. Ohm's Law states that the voltage across a resistor is equal to the current through the resistor multiplied by the resistance. As the capacitor discharges, it takes energy from the resistor, which means that the current through the resistor decreases, and therefore the voltage across the resistor will also decrease.
How do you find unknown value of a resistor when total resistor values and voltage are known in a series circuit?
A: If you know the total resistance and total voltage then you know total current flow for the circuit, this current will be same for every resistor in series however the voltage drop will change for each resistor . So measuring the voltage drop across the resistor in question and divide by the total current will give you the resistor value.
What happens when resistance is varied in a circuit?
A resistor will not change its value, unless the voltage exceeds the designed power capacity of the resistor. As the voltage increases, the current will increase, if the current gets too high it will cause the temperature of the resistor to increase, if the temperature exceeds the power rating of the resistor then the resistance WILL change. If it goes too High in temperature the resistor will open and current will no longer flow. A resistor is used to control current, and indirectly the .voltage depending on the application. Hope This helps. You must use Ohms Law to see the relationship.
How current amplification is occur in a transistor?
A: Vacuum tubes are current amplifiers transistors are voltage amplifier. The voltage drop across the collector resistor causes amplification since very little current in the base will change a large current in the collector.
How does the current in a resistor change if the voltage across the resistor is increased by a factor of 2?
It decreases by a factor of 4
How does the voltage across a capacitor change over time when a current is flowing through it?
When a current flows through a capacitor, the voltage across it increases or decreases depending on the rate of change of the current. If the current is constant, the voltage remains steady. If the current changes rapidly, the voltage across the capacitor changes quickly as well.
What happens to the applied voltage when a change in circuit resistance occurs?
When a dc supply is connected to a resistor, current flows. The current in amps is equal to the supply voltage divided by the resistance in ohms. The power used is the voltage times the current, and that appears as heat in the resistor, which might become hot to touch.
Is the heat loss and current of a resistor affected by being in a parallel circuit or can you just calculate it the same as in series?
The heat generated by any particular resistor depends (at least electrically) solely on the power it dissipates. Power dissipation in a resistor is equal to current squared times resistance, and the current through the resistor is equal to the voltage across it divided by the resistance. If we take a 10 ohm resistor ('your resistor') and put it in a series circuit such that there is 10 volts across your resistor, the current through it will be 1 ampere (10/10=1). the power dissipated will be 10 watts (1^2 * 10=10). If we put your resistor in a parallel circuit that also puts 10 volts across it, then the current and power will be the same. Your resistor does not know or care where the voltage came from. From this point of view, once you get down to the voltage across the resistor, it does not matter what type of circuit it is in. On the other hand, for any given power supply voltage, then the type of circuit and the value of external components certainly does affect the terminal voltage and thus the current through as well as the power dissipated by the resistor. In a parallel circuit, the voltage across your resistor remains basically the same no matter what resistance you put in parallel with it (unless you overload the power supply or the power supply has high internal resistance). In this case, the voltage across the resistor is the same as the power supply, current is I=E/R, R being that resistor only, and power is P=I^2 * R. In a series circuit the current through the resistors is I=E/R, R being the total resistance (including the other resistor(s)). The power dissipation in your resistor will then be P=I^2 * R, I being the series current we just calculated, and R being your resistor only. Since the other resistors affect the current, and since the current is the same no matter where you measure in a series circuit, then the voltage across your resistor and thus the power dissipation will be affected. The voltage across your resistor will be E=I*R, I being the series current we just calculated, and R being your resistor only. So, while the calculation for power dissipated in a particular resistor does not change relative to what type of circuit it is in, the calculation to arrive at the voltage across the resistor and/or the current through it (which you will then need to calculate power) does. Keep in mind there are other mechanical parameters that influence the actual case temperature of the resistor. Physical size of the case, composition, and airflow velocity, if any, will alter the case-to-ambient thermal conductivity. Ambient temperature will also be a factor in the final temperature.
How do you change current into voltage?
Compute the open load voltage of the current source across its shunt resistance.This voltage becomes the voltage source's voltage.Move the current source's shunt resistance to the voltage source's series resistance.Insert the new voltage source into the original circuit in place of the current source.
Why voltage across capacitor cant change instantaneously?
Capacitors resist change in voltage. By definition, the equation is dv/dt = i/c, or rate of change of voltage in volts per second is current in amps divided by capacitance in farads. In order for the voltage to change instantaneously, then dv/dt must be infinity, which means i/c is also infinity. If capacitance is non-zero, then current must be infinity. Since there is no perfect voltage source, or no resistor or wire with perfect zero ohms, then it is impossible to have an infinite current, so it is impossible for the voltage across a capacitor to change instantaneously.
