HARD
12th Odisha Board
IMPORTANT
Earn 100

Derive the expression for the current in a purely inductive a.c circuit. Why is it called wattless current? Draw the phasor diagram for voltage and current for the circuit.

Important Questions on Alternating Currents

HARD
12th Odisha Board
IMPORTANT
An a.c circuit contains resistance. Draw the circuit diagram and calculate the current in the circuit. What is the phase of the current in the resistor with respect to applied emf?
HARD
12th Odisha Board
IMPORTANT

What is alternating current? Prove the following for a.c

(i) Ieff=I02

HARD
12th Odisha Board
IMPORTANT

What is an alternating current? Prove the following for a.c

(ii) Iavg=2I0π for the positive half cycle.

HARD
12th Odisha Board
IMPORTANT
Discuss the principle, theory, and construction of a transformer. What are the various types of losses in it? Mention its two main uses.
HARD
12th Odisha Board
IMPORTANT
Obtained an expression for the average power in an a.c circuit containing resistance. Show that it is equal to the product of the virtual values of emf and the current of the circuit.
HARD
12th Odisha Board
IMPORTANT
The emf and current of an a.c circuit containing L,C and R are given by ε=ε0sinwt and I=I0sinwt+ϕ. Show that the average power of the circuit is Pavg=εvIvcosϕ, where εv and Iv stand for virtual emf and virtual current respectively.
HARD
12th Odisha Board
IMPORTANT
Show that the current leads the applied voltage by 90° in a pure capacitive a.c circuit. Find the impedance of the circuit and discuss its variation with the frequency of the a.c source. If f=50Hz, C=2μF. What is the value of the same.
MEDIUM
12th Odisha Board
IMPORTANT
Deduce an expression for the power of an a.c circuit containing an inductance. Explain what is power factor in the purely inductive circuit.