Skip to content
dronacharya.ai
← JEE Advanced 2021 · Paper 2
PhysicsNumerical+2Question 12 of 57

JEE Advanced 2021 · Paper 2, Physics question 12

Passage

Question Stem for Question Nos. 11 and 12

In a circuit, a metal filament lamp is connected in series with a capacitor of capacitance C μ\muF across a 200 V, 50 Hz supply. The power consumed by the lamp is 500 W while the voltage drop across it is 100 V. Assume that there is no inductive load in the circuit. Take rms values of the voltages. The magnitude of the phase-angle (in degrees) between the current and the supply voltage is φ\varphi. Assume, π3≈5\pi\sqrt3 \approx 5.

The value of φ\varphi is ____.

Answer and worked solution

Official answer: 55

Phase angle. The current is in phase with the lamp voltage, so
cos⁡φ=VRV=100200=12  ⟹  φ=60∘.\cos\varphi=\frac{V_R}V=\frac{100}{200}=\frac12\implies\varphi=60^\circ.