JEE Mains · Physics · STD 12 - 3. current electricity
The total length of potentiometer wire AB is 50 cm in the arrangement as shown in figure. If P is the point where the galvanometer shows zero reading then the length AP is _________ cm .
- A 15
- B 30
- C 25
- D 20
Answer & Solution
Correct Answer
(B) 30
Step-by-step Solution
Detailed explanation
\(\frac{6}{ R _{ AP }}=\frac{4}{ R _{ PB }} ;\) \(\ell_{ AP }+\ell_{ PB }=50\)....(i) \(\frac{ R _{ AP }}{ R _{ PB }}=\frac{\ell_{ AP }}{\ell_{ PB }}=\frac{3}{2}\) \(\ell_{ AP }=\frac{3}{5} \times 50=30 cm\)
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