Effective or RMS Value of AC

Author:Odisha Board
12th Odisha Board
IMPORTANT

Important Questions on Effective or RMS Value of AC

HARD
IMPORTANT

Correct: Average value of a.c. is I02.

HARD
IMPORTANT

Correct: The r.m.s value of an a.c. is I02.

HARD
IMPORTANT

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

(i) Ieff=I02

HARD
IMPORTANT

Write down the equation that represents a sinusoidal a.c. Obtained expression for its mean value and rms value over one cycle in terms of the peak current. Why is a.c considered to be more dangerous than d.c?

 

HARD
IMPORTANT

Differentiate between direct current and alternating current. Obtained an expression for the rms value of the latter i.e., a.c over cycle. What is the difficulty in using the average value of a.c?

HARD
IMPORTANT

A current is made of a 3amp d.c. component and an a.c component given by I=4sinwt amp. Find an expression for the resultant current and calculate its effective value. [Hint: I=Id.c+Ia.c find the square of I and hence obtained Irms].

HARD
IMPORTANT

If the electric current in a circuit is given by I=I0tτ for some time, find the RMS current for the period from t=0 to t=τ.

MEDIUM
IMPORTANT

60Hz a.c. circuit has a voltage of 120 volts and current of 6 amp. (effective values). Find the maximum values of these quantities. What is the instantaneous value of the voltage 1720 sec. after the voltage has zero value?

MEDIUM
IMPORTANT

Alternating current in a circuit is given by I=50sin400πt. Find the frequency and the RMS value of the current.

EASY
IMPORTANT

Write down an equation representing alternating current and explain the symbols used in it.

EASY
IMPORTANT

Differentiate between RMS value and average value of AC over a cycle.