A Wheatstone bridge is said to be completely balanced when:
A. Potential difference across the galvanometer is zero.
B. Current through the galvanometer is maximum.
C. The battery supplies zero current.
D. All four resistors have exactly identical values.
Answer: Option A
Solution (By JKSSB Mock Tests)
A Wheatstone bridge circuit consists of four arms with resistances P, Q, R, S and a galvanometer in the middle. It is balanced when no current flows through the galvanometer arm. This happens exclusively when the potentials at the two ends of the galvanometer are equal, meaning the potential difference across it is exactly zero (P/Q = R/S).
Explanation:
In series circuits, current is the same through all components because there's only one path for charge flow. Voltage divides across components proportional to resistance (V = IR). Resistance and power vary per component. Memory aid: 'Series: same current; Parallel: same voltage'. This fundamental circuit property is frequently tested in competitive exams to assess basic electronics understanding. Always apply Kirchhoff's current law: current entering a junction equals current leaving; in series, no junctions, so current constant.
Explanation:
Q = mcΔθ = 2 × 4200 × 10 = 84,000 J = 84 kJ. Large specific heat of water makes it useful for cooling and climate moderation. Always check units: mass kg, c J/kg°C, ΔT °C.
No comments yet. Be the first to start the discussion!