Question

A resistor of $6k\Omega$ with tolerance $10$% and another of $4k\Omega$ with tolerance $10$% are connected in series. The tolerance of combination is about

• A. $5$%
• B. $10$%
• C. $12$%
• D. $15$%

Answer 1

Answer: (B)

$10$%

Let the resistances are $R_1=6k\Omega$ and $R_2=4k\Omega$.

Tolerence in the resistances : $\Delta R_1=600\Omega$ $\Delta R_2=400\Omega$
Total resistance of the combination $R_{eq}=R_1+R_2=6+4=10k\Omega$

Total tolerance in the equivalent resistance: $\Delta R_{eq}=\Delta R_1+\Delta R_2=600+400=1k\Omega$

Hence percentage tolerance of combination $=\frac{1k\Omega }{10k\Omega }\times 100=10$ %