Question

If a $400\Omega$ resistance is made by adding four $100\Omega$ resistance of tolerance $5\%$, then the tolerance of the combination is ?

• A. $20\%$
• B. $5\%$
• C. $10\%$
• D. $15\%$

Answer 1

The correct option is B $5\%$

$T=\frac{R_1{T}_1+R_2{T}_2+R_3{T}_3+R_4{T}_4}{R_1+R_2+R_3+R_4}$

$=\frac{100\times 5\times 4}{400}$

$=5$%