A rectangular block of copper has sides of length 13 cm, 25 cm, and 41 cm. If th
ID: 1316439 • Letter: A
Question
A rectangular block of copper has sides of length 13 cm, 25 cm, and 41 cm. If the block is connected to a 5.0 V source across two of its opposite faces of the rectangular block, what are the currents that the block can carry? (a) the maximum currentA
(b) the minimum current
A A rectangular block of copper has sides of length 13 cm, 25 cm, and 41 cm. If the block is connected to a 5.0 V source across two of its opposite faces of the rectangular block, what are the currents that the block can carry? (a) the maximum current
A
(b) the minimum current
A (a) the maximum current
A
(b) the minimum current
A
Explanation / Answer
We know that Resistance is equal to
R = pL/A where p is resistivity , L is length and A is Area.
Resistivity of copper = 1.7*10-8 ohm- meter
Now first of all we consider the end when length is 13 cm then A = 25*41 cm2
Now Converting all the dimensions in meter and putting in to the formula
we get R1= 2.156*10-8 ohm
Similarly considering resistance when length is 25 cm
then R2 = 7.973*10-8 ohm
When length is 41 cm
then R3 = 21.446*10-8 ohm
Hence we come to know that resistance is minimum in first case therefore current will be maximum and in third case resistance is maximum therefore current will be minimum
I1 = V/R1 = 5 /R1 = 2.319*108 Ampere
I3 = V/R3 = 5/R3 = 0.233*108 Ampere