Question

Three resistors R1= 1 Ω , R2 = 100 Ω , R3 = 1000 Ω are connected in parallel. Which relation holds true?

• A. Req. < 1
• B. 1 > Req> 100
• C. Req = 100
• D. 1 > Req > 1000

Answer 1

The correct option is A Req. < 1

$\frac{1}{Req.}$ = $\frac{1}{R_1}$ + $\frac{1}{R_2}$ +$\frac{1}{R_3}$
1/Req.= $\frac{1}{1}$ + $\frac{1}{100}$ +$\frac{1}{1000}$
1/ Req = 1 + 0.01 + 0.0001
1/ Req = 1.0101
Req = 1/ 1.0101
Req. < 1 ( 0.98 )
Req. < 1