HARD
12th ICSE
IMPORTANT
Earn 100

Show, with explanation, the variations of emf and current with time in AC circuits having pure resistance, pure inductance and pure capacitance.

Important Questions on Alternating Current

HARD
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 6
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
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 6
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
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 7
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
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 8
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
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 9
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
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 10
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?
MEDIUM
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 11
What is impedance of an AC circuit? A capacitor C and a resistor R are connected in series in an AC circuit. Derive expression for the impedance Z of the circuit. Draw phasor diagram.
MEDIUM
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 12 - Alternating Current>QUESTIONS>Q 12
In an alternating-current circuit an inductance L, a capacitance C and a resistance R are connected in series. Derive expression for the impedance and the phase angle. What is the impedance at resonance?