Question

If resistance of potentiometer wire = 15 r then calculate the balance length l :

• A. 320 cm
• B. 200 cm
• C. 400 cm
• D. 100 cm

Answer 1

Answer: (A)

320 cm

Answer 2

P.D of ext. ckt = f × balance length

E/2 = × l

or E/2 = $\frac { E } { 600 }$ × $\frac { 15 \mathrm { r } } { 16 \mathrm { r } }$ × l

\ l = $\frac { 600 \times 16 } { 30 }$ = 320 cm