A single-loop circuit contains three ideal elements connected in the following order…
PHYSICS · Multi-part · CBSE · Physics · Current Electricity · Current Electricity
Problem
A single-loop circuit contains three ideal elements connected in the following order when viewed clockwise:
• a 6 V battery whose positive terminal is on the right
• a resistor R
• a 9 V battery whose positive terminal is on the left
A reference point P is located at the junction between the two batteries.
Different students choose different starting points and traversal directions when writing a potential-difference sum for the loop.
(a) Starting at point P and moving clockwise, list the potential differences across the three elements in the order encountered, assigning an algebraic sign (+ or −) to each term. Do not substitute numerical values.
(b) Repeat part (a) for a traversal that begins at P but moves counterclockwise.
(c) A third student starts at the midpoint of the resistor and travels clockwise until returning to the same point. Write the algebraic sum of potential differences encountered, again without substituting numerical values.
(d) For each traversal in parts (a)–(c), consider the cumulative algebraic potential change after the first two elements have been traversed (before the loop is closed). Rank these three intermediate results from most positive to most negative and justify your ranking without performing arithmetic with the stated voltages.
(e) Explain how your answers demonstrate that the total potential change around any complete traversal of the closed loop is zero, regardless of the chosen starting point or direction.