Please solve this equations
Dear student,
A) R = ρL/A
L = 1 m
R = 6 ohm
So, according to the formula R is directly proportional to L
So, when R = 6 ohm then L is 1 m accordingly when L = 70 cm = 0.7 m then
R = 0.7 × 6
R = 4.2 ohm
B) Let the two unknown resistors be R1 and R2
According to question,
Req (in series) = 80 ohms
So, R1 + R2 = 80
R1 = 80 - R2 --------- (1)
Further,
Req (in parallel) = 20 ohms
Req = R1 × R2/( R1 + R2)
From (1)
20 = (80 - R2) R2/ 80
1600 = 80 R2 - R22
R22 -80 R2 + 1600 = 0
On solving we get, R2 = 40 and 40
Therefore, the two resistors are 40 ohm each
Hope this information will clear your doubts about topic.
For more queries just ask in a separate thread here on the forum and our experts will try to help you out as soon as possible.
Regards
A) R = ρL/A
L = 1 m
R = 6 ohm
So, according to the formula R is directly proportional to L
So, when R = 6 ohm then L is 1 m accordingly when L = 70 cm = 0.7 m then
R = 0.7 × 6
R = 4.2 ohm
B) Let the two unknown resistors be R1 and R2
According to question,
Req (in series) = 80 ohms
So, R1 + R2 = 80
R1 = 80 - R2 --------- (1)
Further,
Req (in parallel) = 20 ohms
Req = R1 × R2/( R1 + R2)
From (1)
20 = (80 - R2) R2/ 80
1600 = 80 R2 - R22
R22 -80 R2 + 1600 = 0
On solving we get, R2 = 40 and 40
Therefore, the two resistors are 40 ohm each
Hope this information will clear your doubts about topic.
For more queries just ask in a separate thread here on the forum and our experts will try to help you out as soon as possible.
Regards