HARD
12th ICSE
IMPORTANT
Earn 100

Show mathematically that in an AC circuit containing inductance only, the current lags behind the voltage by π/2.

Important Questions on Alternating Current

HARD
12th ICSE
IMPORTANT
Show mathematically that in a pure capacitive AC circuit, the current leads the voltage by π/2.
HARD
12th ICSE
IMPORTANT
Show, with explanation, the variations of emf and current with time in AC circuits having pure resistance, pure inductance and pure capacitance.
HARD
12th ICSE
IMPORTANT
An AC emf V-V0 sin ωt is applied across a pure inductance L. Obtain expressions for (i) the current I
EASY
12th ICSE
IMPORTANT
An AC emf V-V0 sin ωt is applied across a pure inductance L. Obtain expressions for  (ii) the inductive reactance XL in the circuit. Draw a phasor diagram showing emf V0, current I0 and their phase difference ϕ.
HARD
12th ICSE
IMPORTANT
Explain the meaning of ‘reactance’. Derive expression for the reactance of an inductor L connected across an AC source. Give its unit. Show that no power is dissipated in an inductor when AC passes through it.
MEDIUM
12th ICSE
IMPORTANT
Obtain the relation for the current I=I0 sin ωt- π/2 for a pure inductor across which an alternating emf V=V0 sin cot is applied. 
MEDIUM
12th ICSE
IMPORTANT
Obtain the relation O=I0 sinωt+π/2 and XC= 1/ωC for a pure capacitor across which an alternating emf V=V0 sin ωtis applied. Draw a phasor diagram showing emf V, current I and their phase difference ϕ.
MEDIUM
12th ICSE
IMPORTANT
A capacitor C is connected to an AC voltage source V=V0 sin ωt. Draw a circuit diagram for it. Obtain an expression for the current / flowing in the circuit. Express it as a sin function. What is the phase difference between current I and voltage V? What is the reactance of the capacitor?