Govt. Exams
Entrance Exams
Power factor (lagging) is improved by adding shunt capacitance, which creates a leading current that offsets the lagging component.
Hall effect sensors detect the magnetic field strength by measuring the Hall voltage generated when a current-carrying conductor is placed in a perpendicular magnetic field.
RTDs exhibit a nearly linear relationship between resistance and temperature: Rt = R₀(1 + αt + βt²), where the linear term dominates.
Mutual inductance depends on geometry, coil configuration, and medium properties, but NOT on the current flowing through them.
Thermocouples generate EMF (Seebeck effect) proportional to the temperature difference between junctions and don't require external power.
Moving iron instruments deflect based on the magnitude of current/voltage regardless of direction. The iron core is attracted by the magnetic field produced by the coil in both AC and DC.
At balance condition in Wheatstone bridge: R₁/R₂ = R₃/R₄, which can be rearranged to R₁ × R₄ = R₂ × R₃
Owen bridge is specifically designed for accurate measurement of unknown inductance and capacitance values in AC circuits.
Using shunt formula: S = (Ig × Rg) / (I - Ig) = (5×10⁻³ × 10) / (5 - 5×10⁻³) ≈ 0.01 Ω
For a boost converter, Vo/Vin = 1/(1-D), where D is duty cycle. 48/24 = 1/(1-D) → 2 = 1/(1-D) → 1-D = 0.5 → D = 0.5 or 50%
