A resistor has a resistance of 176 ohm . How many of these resistors should be connected in parallel so that their combination draws a current of 5 amperes from a 220 volt supply line ?
Answers
Answered by
39
As V= 220V and I = 5A
So Re = 220/5 = 44ohm (effective resistance)
Now for parallel connected resistance we have,
1/Re = 1/R+1/R+.....
or 1/Re = n/R
n = 1/Re× R
or n = 1/44×176 = 4
Ans: So 4 resistors of 176ohm must be joined parallel for effective resistance of 44 ohm.
So Re = 220/5 = 44ohm (effective resistance)
Now for parallel connected resistance we have,
1/Re = 1/R+1/R+.....
or 1/Re = n/R
n = 1/Re× R
or n = 1/44×176 = 4
Ans: So 4 resistors of 176ohm must be joined parallel for effective resistance of 44 ohm.
Answered by
10
For Resistors in Parallel,
1/R(total) = 1/R₁ + 1/R₂ + 1/Rₓ
From Ohm's Law
V = IR
220 = (5)R
R = 44 Ω
Therefore
1/44 = No. of 176Ω Resistors * 1/176
Let no. of 176Ω Resistors be x
Then 1/44 = x/176
x = 4
Therefore, 4 resistors of 176Ω ( in parallel) are required to carry 5 A on a 220 V line.
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