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Any resistor in a circuit that has a voltage drop across it dissipates electrical power. This electrical power is converted into heat energy hence all resistors have a power rating. This is the maximum power that can be dissipated from the resistor without it burning out.
What will happen to the power dissipated in the resistor as the resistance is decreased?
As you may know, the unit Watt (W) is how we express power, and the formula for power is P (power) = I (current) x E (voltage). However, if you increase the value of the resistor, current will decrease, and the resistor’s power dissipation will decrease as well.
Which resistor dissipates more power in series?
In general, if the power consumed would depend on the circuit structure. But for a simple case, such as two resistors connected in series versus the same resistors connected in parallel (with identical voltage sources in both), the power dissipated in the parallel combination will be greater.
Does high resistance increase current flow?
The current is directly proportional to the voltage and inversely proportional to the resistance. This means that increasing the voltage will cause the current to increase, while increasing the resistance will cause the current to decrease.
What happens when resistance decreases?
Likewise, if we increase the resistance, the current goes down for a given voltage and if we decrease the resistance the current goes up. Which means that if resistance is high current is low and if resistance is low current is high.
Why does increasing resistance decrease power?
If you attach a small resistance, the source doesn’t need to work very hard to get an amount of current flowing so little power is expended. If you attach a large resistance the source needs to work much harder to get the same current flowing, thus a lot of power is expended.
What happens if the resistance decreases?
What happens to resistance in a series circuit?
In a series circuit, the total resistance across all of the components (the ‘net resistance’) increases as more components are added. The two resistors have the same current through them. The potential difference across them will be different if they have different resistances.
How much power is dissipated by the circuit of parallel circuit?
When the bulbs are connected in parallel, each bulb has 120 V across it, each draws 1/3 A, and each dissipates 40 watts. In this circuit, all bulbs glow at their full brightness. The total power dissipated in the circuit is three times 40, or 120 watts (or 3(1/3) A × 120 V = 120 W).
Does a higher resistance dissipate more power?
This is the result to remember: the power dissipated in the load is maximized when the load resistance is matched to the source’s own internal resistance. Now, any circuit you would reasonably call a “voltage source” must have a low internal resistance compared to typical load resistances.