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As the name implies, resistance resists current. In the mathematical formula, where E is electromotive force (voltage):- I = E/R If you increase the value of R (resistance), then the value of I (current) decreases.
Wiki User
∙ 14y ago
Wiki User
∙ 14y agoBecause of power losses.
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How does load current varies with the load resistance?
Load current is related to load resistance by an inverse relationship. The load current increases linearly as load resistance decreases. Remember, the less resistance, the more current.
Is it true that the bigger sized cable offers less resistance to current flow?
yes
Why might the current in a short circuit be higher than the current in the original circuit?
The current in a short circuit may be very high because the resistance in the short circuit is probably less than the resistance in the original circuit.
If you doubled the load resistor in a wheatstone bridge. the load current would not be half as much Why not?
Because by increasing the load resistance, the total circuit resistance is reduced. This means with less resistance, there is more current drawn from the source. Doubling the size of a load resistor increases the load current.
Why shunt resistance must be small in ammeter?
An ammeter has to measure to current flowing through the circuit. Resistance offers an obstruction to the current flow. So, if the resistance of an ammeter is large , the current measured by the ammeter will be quite less as compared to the actual amount of current flowing through the circuit which is undesirable. If ammeter has zero resistance , then it will give the exact value of current. But this is not practically possible because every material has some value of internal resistance which we can't control. For this reason , ammeter must have small resistance
Why the zero of the ohmmeter scale is usually at the right end of the scale and reading increase towards the left?
Because the meter is actually measuring the current through the resistor, and the two quantities ... current and resistance ... are inversely proportional. So when the meter measures more current, it has to read less resistance, whereas higher resistance will result in less current. So the numbers for resistance have to be printed "backwards" on the meter scale.
How does load current varies with the load resistance?
Load current is related to load resistance by an inverse relationship. The load current increases linearly as load resistance decreases. Remember, the less resistance, the more current.
Does current change in a circuit having bulb in series with a resistance?
Absolutely the more Resistance is put in series the less current Will flow.
What amount of resistance has the least amount of current flow?
The higher the resistance, the less current will flow through it (while the supply voltage remains constant).
Is the resistance in the start winding greater or less than the resistance in the run winding?
The resistance in the start winding is greater because it is longer and thinner and has the greatest resistance to current flow
What did ohm discover about thr relationship between these three factors currentvoltageandresistance?
The law named after him is: V = IR (in words: voltage = current x resistance) It is more intuitive if you express it solved for current, since current can be thought of as the dependent variable: I = V/R This shows that more voltage will result in more current, while more resistance will result in less current. Of course, in the SI the units are chosen in such a way that the proportionality constant is one (and doesn't appear in the equation).
How does resisitance affect currents?
The higher the resistance the less current can pass through therefore the current will be lower.
What does resistor perform?
A resistor's resistance is measured in ohms. The higher the resistance the less current will flow with a constant voltage applied across the resistor. In terms of Ohm's Law Voltage = Current x Resistance.
Can an overhead conductor carry more current on a cold day as compared to a hot day?
The only limit on how much current the conductor can carry, regardless ofthe weather, is the amount of current that causes the conductor to melt.The current in such a conductor depends on the voltage between its ends,and on the resistance of the conductor. The resistance of the conductor issomewhat less when it's cold, so a given voltage would result in more current.
How can electric current be changed in Omh's Law?
Ohm's Law: V = IR Solving for current: I = V/R To affect the current, you can either change the voltage (more voltage --> more current), or the resistance (more resistance --> less current).
What does ohm sign symbolize?
The ohm is the unit of electrical resistance to current flow. More ohms (more resistance), the less current will flow. Less ohms (less resistance), the more current will flow. One ohm is defined as the amount of resistance that will cause one ampere of current to flow if the supply voltage is one volt. Ohm's law states that amps = volts / ohms So, if you had a 12 volt battery, and you connected a load, say a heating element that had a resistance of 3 ohms, how much current would flow in the circuit? amps = 12 volts / 3 ohms amps = 4
Does a lamp with a thick filament draw more or less current than a lamp with a thin filament?
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
