Question

If two resistors of resistance R1=(24 ± 0.5)ohm and R2=(8 ± 0.3)ohm are connected in Parallel . Find % error.

Answer 1

Answer:

Here, R1=16ohm,ΔR1=0.3Ω

R2=48ohm,ΔR2=0.5Ω,Rp=?

1Rp=1R1+1R2=116+148=3+148=448=112

Rp=12ohm

On differentating, 1Rp=1R1+1R2, we get −ΔRpR2p=−ΔR1R21−ΔR2R22

∴ΔRp=ΔR1(RpR1)2+ΔR2(RpR2)2=0.3(1216)2+0.5(1248)2

= 0.16875+0.03125=0.20ohm

ΔRpRp×10=0.2012×100=1.6%