If the cross-section of a wire of fixed length is doubled, how does the resistance of that wire change? (this is for studying fo
1 answer:
You might be interested in
Answer:
each resistor is 540 Ω
Explanation:
Let's assign the letter R to the resistance of the three resistors involved in this problem. So, to start with, the three resistors are placed in parallel, which results in an equivalent resistance defined by the formula:
Therefore, R/3 is the equivalent resistance of the initial circuit.
In the second circuit, two of the resistors are in parallel, so they are equivalent to:
and when this is combined with the third resistor in series, the equivalent resistance () of this new circuit becomes the addition of the above calculated resistance plus the resistor R (because these are connected in series):
The problem states that the difference between the equivalent resistances in both circuits is given by:
so, we can replace our found values for the equivalent resistors (which are both in terms of R) and solve for R in this last equation: