If all the resistors in a circuit are changed by the same amount, including internal resistances of voltage and current sources, the voltages throughout the circuit remain unchanged. The currents will change though.
If the internal resistances of voltage and current sources remain unchanged it is more complicated and will have to be computed on a case by case basis.
The effective resistance between opposite corners of a cube comprised of twelve 6 ohm resistors, one at each edge, is 5 ohms. There are several ways to solve this. One approach is to build a system of 12 equations in 12 unknowns, and solve them. Another approach is this... Consider that there are three resistors leaving the input node, and there are three resistors entering the output node. In between those three resistors, there are six resistors in a criss-cross matrix. (Draw it out, flattened, to see this.)Inspecting the six resistors in the center, you note that they are completely symmetrical. Since they are symmetrical, you can conclude that the voltage at the junction between the three input resistors and the six others is the same voltage. The same goes for the three output resistors. Said another way, the voltage across the three input resistors and the three output resistors is the same. Given two or more nodes in a circuit having the same voltage, you can draw a wire connecting them, i.e. a resistor of zero ohms. This does not change the characteristics of the circuit in any way, because zero voltage across any resistance is still zero amperes. Now that you have made these connections, look at the circuit. It has simplified to three parallel resistors, in series with six parallel resistors, in series with three parallel resistors. Three 6 ohm resistors in parallel is 2 ohms. Six 6 ohm resistors in parallel is 1 ohm. Three more 6 ohm resistors in parallel is 2 ohms. The total resistance is 2 + 1 + 2 ohms, or 5 ohms.
Given twelve 1 KOhm resistors, connected in the shape of a cube, in order to determine the net resistance between opposite corners, first draw the cube in two dimensions. (Try this at each step before continuing, so you can understand the lesson as it unfolds.)There are three resistors leaving the initial vertex, and three resistors entering the final vertex. In between those six resistors, are six more resistors, each pair connected together on one end, and to two other resistors on the other end.If every resistor has the same value, then (by symmetry), the voltage on the ends of the first three resistors must be the same. Similarly, the voltage on the ends of the last three resistors must be the same.If two points in a circuit have the same voltage, then (for purposes of analysis) you can consider them to be shorted together. That short does not change the results, as there is no current flowing through that short.With the bottom ends of the first three resistors shorted, and with the top ends of the last three resistors shorted, the circuit degrades into three resistors in parallel, in series with six more resistors in parallel, in series with three more resistors in parallel.Three 1 KOhm resistors in parallel have a net resistance of 333 ohms. Six have a net resistance of 167 ohms. Two 333 ohm resistors and one 167 ohm resistor in series have a net resistance of 833 ohms, or 5/6 of 1 KOhms.Note: This technique does not work if the resistors are not all the same value. In that case, you would need to solve 12 equations in 12 unknowns, looking at the partial currents in each branch.
Simply put, the purpose of a resistor is to 'resist' the flow of current. Ohm's Law tells us that for a given voltage, the larger the resistance, or value of that resistor, the lower the current that will flow. Ohm's Law states that I (current) = E (voltage) / R (resistance) - where current is measured in amps, voltage is measured in volts and resistance is measured in ohms.
The total effective resistance of resistors in series is the sum of the individual resistances.Three 60-ohm resistors in series have a total effective resistance of (60 + 60 + 60) = 180 ohms.
A: That will happen anytime the voltage source is not able to provide the power needed for the load. If the load exceed the power available from the source the voltage will be reduced as IR drop from the source
resistors is a most common electronic component and is used to control the voltage and current in a electronic circuit. resistors is inversely proportional to amount of power supplied,given by (power= voltage *current).
Resistor values are given in ohms. A value may be selected to deliver a specific current at a given voltage. This is given in what is known as Ohm's Law where: Voltage (V) = Current (A) X Resistance (Ohm) A 12ohm resistor placed across a 12V battery would pass 1Amp of current and put out 12W of heat.
The effective resistance between opposite corners of a cube comprised of twelve 6 ohm resistors, one at each edge, is 5 ohms. There are several ways to solve this. One approach is to build a system of 12 equations in 12 unknowns, and solve them. Another approach is this... Consider that there are three resistors leaving the input node, and there are three resistors entering the output node. In between those three resistors, there are six resistors in a criss-cross matrix. (Draw it out, flattened, to see this.)Inspecting the six resistors in the center, you note that they are completely symmetrical. Since they are symmetrical, you can conclude that the voltage at the junction between the three input resistors and the six others is the same voltage. The same goes for the three output resistors. Said another way, the voltage across the three input resistors and the three output resistors is the same. Given two or more nodes in a circuit having the same voltage, you can draw a wire connecting them, i.e. a resistor of zero ohms. This does not change the characteristics of the circuit in any way, because zero voltage across any resistance is still zero amperes. Now that you have made these connections, look at the circuit. It has simplified to three parallel resistors, in series with six parallel resistors, in series with three parallel resistors. Three 6 ohm resistors in parallel is 2 ohms. Six 6 ohm resistors in parallel is 1 ohm. Three more 6 ohm resistors in parallel is 2 ohms. The total resistance is 2 + 1 + 2 ohms, or 5 ohms.
Resistor values are given in ohms. A value may be selected to deliver a specific current at a given voltage. This is given in what is known as Ohm's Law where: Voltage (V) = Current (A) X Resistance (Ohm) A 12ohm resistor placed across a 12V battery would pass 1Amp of current and put out 12W of heat.
Resistors have resisting power(resists the electric power).Due to having the resistive property, the name resistor is given to such electrical device.
If the bulbs are in a series circuit the voltage drops at each bulb drops as additional bulbs are added. In a parallel circuit the voltage is constant no matter how many bulbs are added.
Given twelve 1 KOhm resistors, connected in the shape of a cube, in order to determine the net resistance between opposite corners, first draw the cube in two dimensions. (Try this at each step before continuing, so you can understand the lesson as it unfolds.)There are three resistors leaving the initial vertex, and three resistors entering the final vertex. In between those six resistors, are six more resistors, each pair connected together on one end, and to two other resistors on the other end.If every resistor has the same value, then (by symmetry), the voltage on the ends of the first three resistors must be the same. Similarly, the voltage on the ends of the last three resistors must be the same.If two points in a circuit have the same voltage, then (for purposes of analysis) you can consider them to be shorted together. That short does not change the results, as there is no current flowing through that short.With the bottom ends of the first three resistors shorted, and with the top ends of the last three resistors shorted, the circuit degrades into three resistors in parallel, in series with six more resistors in parallel, in series with three more resistors in parallel.Three 1 KOhm resistors in parallel have a net resistance of 333 ohms. Six have a net resistance of 167 ohms. Two 333 ohm resistors and one 167 ohm resistor in series have a net resistance of 833 ohms, or 5/6 of 1 KOhms.Note: This technique does not work if the resistors are not all the same value. In that case, you would need to solve 12 equations in 12 unknowns, looking at the partial currents in each branch.
Simply put, the purpose of a resistor is to 'resist' the flow of current. Ohm's Law tells us that for a given voltage, the larger the resistance, or value of that resistor, the lower the current that will flow. Ohm's Law states that I (current) = E (voltage) / R (resistance) - where current is measured in amps, voltage is measured in volts and resistance is measured in ohms.
Current decreasesWhen voltage remains constant and resistance increases the current in the circuit will reduce.More informationV=IRwhere V is voltage,I is current andR is resistance.From the above equation,R=V/I, and hence resistance is indirectly proportional to current.Therefore, an increase in resistance would have the effect of decreased current.NB: this holds true only as long as the voltage remains constant.Another opinionHowever, this is only true in the case of a circuit connected in series.When circuits are connected in parallel, the opposite happens. If there is an increase in the amount of resistors in parallel, the total resistance of the circuit then decreases and the current increases subsequently.Yet another viewNo, that's not stated right.If more resistors are added in parallel - so that the circuit's overall total resistance decreases and its total current increases - that is NOT in any way the opposite of what this question is asking about...Let's make this crystal clear, so that there is no confusion: "an increase in the amount of resistors" is NOT the same as "an increase in resistance".So a parallel circuit behaves EXACTLY the same as a series circuit: if its overall resistance increases, the overall current going through the parallel circuit decreases AND if its overall resistance decreases, the overall current going through the parallel circuit increases.Actually, the second opinion is correctIn a parallel circuit, there are more branches to allow electrons back to the power supply, so current increases. With more resistors in a circuit, the overall resistance in a parallel circuit DECREASES.In a series circuit, current is the same throughout. So if more resistors are added, resistance INCREASES and so current DECREASES.
The total effective resistance of resistors in series is the sum of the individual resistances.Three 60-ohm resistors in series have a total effective resistance of (60 + 60 + 60) = 180 ohms.
In long range,electric current can flow only when the wires are given high voltage.The voltage is about 20-30kV.eg.lightning. ---------------------------------------- Current of any voltage can flow in a wire. However, the larger the current is, the larger the resistance to flow and the greater the loss of energy during transmission. Therefore, to transfer the same amount of energy per second (power) without as much loss of energy due to resistance, current needs to be lowered by increasing the voltage since Power = Current * Voltage.
the voltage which is given for creating magnetic field in a generator is known as excitation voltage.