a resistor in a circuit has a current through it of 0.20 A when the potential difference across is 15V. calculate the resistance
1 answer:
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Answer:
Decreases, Increases
Explanation:
Resistance is parallel can be calculated using
1/Req = 1/R1 + 1/R2 + 1/R3 +....
Then, as more resistor is added in parallel the equivalent resistance is reduced.
Let use a simple sample
Let all the resistor have equal resistances
Let say R = R1 = R2 = R3 =...Rn
Then, 1/Req = 1/R1 + 1/R2 + 1/R3 +....
1/Req = 1/R + 1/R + 1/R +.... 1/Rn
Req = R/n
Check attachment on how I got that.
This implies that, the equivalent resistance will always be less than the original resistance, since n>1
So, as n increases (I.e. as the number of resistance increases), the equivalent resistance reduces.
B. Now, to know if the current reduces or increases
Using Ohms law
V = iR
Then, I = V/R
So, let assume the voltage is constant, then, the current is inversely proportional to the resistance, so as we know that the resistance is reducing, then the current will be increasing.
So current increase as we add more resistor in parallel to a circuit
