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#maximum power

2 public questions tagged with this topic.

Power in AC Circuits - Power Factor and Wattless Current

What is the condition for maximum power dissipation in a series LCR circuit?

**Power factor** cos φ = R/Z, 0≤cos φ≤1, at resonance cos φ=1 maximum power, pure L or C cos φ=0 zero average power, current wattless because energy stored returned. Instantaneous power when current maximum in pure L: I=I_peak, V=0 because V leads 90°, so P= V I =0 at that instant, average zero. Maximum power dissipation in a series LCR circuit occurs at resonance, where X_L = X_C , making the impedance equal to the resistance ( Z = R ). At this point, the power factor ( cos Φ ) is 1, and power ( P = I² R ) is maximized. Applying X_L

Ref: NCERT > Physics Book > Alternating Currents > Power in AC Circuits - Power Factor and Wattless Current

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Potentiometer, Conductivity and Special Cases

In a circuit with a battery, why does the internal resistance of the battery affect the maximum power delivered to an ex

**Potential difference drop** across resistor when current flows because charges lose potential energy qV = I² R t as heat, field E = V/l drives drift, maintaining current. At very high E, velocity saturation or heating changes τ, causing non-ohmic behaviour. Maximum power transfer occurs when the external resistance equals the internal resistance ( R = r ), as P = I² R = (ε / (R + r))² R . Internal resistance limits current, influencing the power distribution. Applying I = n e A v_d, R = ρ l/A, R_t = R₀[1+αΔT], Kirchhoff's ΣI=0, ΣV=0, R_eq series/parallel, V = ε - I r and

Ref: NCERT > Physics Book > Current Electricity > Potentiometer, Conductivity and Special Cases

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