Wattless current

EXPLANATION : • Wattless Current:When in a circuit, there is onlya Capacitor or inductor,power dissipation becomes zero even though the current is flowing through it. This current is known as wattless current. • So Thiswattless currenthappens in a purely inductive or capacitive circuit. • Wattles current occurs in a circuit when the power dissipated is zero. • As the name suggests wattless means no watt. Watt is the unit of Power. ∴ O ption 2) is the correct choice . NTA has announced the !The exam was held from 6th to 15th April 2023 across various Indian cities and 24 cities outside India. The online application process was active from 14th February to 12th March (9:00 pm). The NTA released the JEE Main 2023 Result (Session 1) on 7th Feb 2023 for the exam which was scheduled from 24th January 2023 to 31st January 2023.Candidates who have qualified in the examination will have to go under counselling.

Wattless Current The current which consumes no power is called wattless current or idle current. In a circuit containing pure inductor or capacitor, the Hence, the average power in a purely inductive or capacitive circuit is zero even though a current is passed through it. This current is called wattless current. Wattful Current At From: \[\therefore\cos\theta=\cos 0°=1\] \[\therefore P_$ is known as the In practice, a low frequency choke coil is made of insulated copper wire on a soft iron core, while a high frequency choke coil has air as core. Previous:

CONCEPT: • Wattless current:The current inAC circuit is said to be wattless currentif the average power consumed in such circuit corresponds to zero and such current is also called idle current. The average power of an AC circuit is given by: P av= E rmsI rmscos ϕ The current I rmscan be resolved into two components i.e. along with parallel and perpendicular components. • The Component I rms cosϕis along E rms. Herethe phase angle between I rms cosϕ and E rmsis zero. P av= E rms(I rmscos ϕ) cos 0 = E rmsI rmscos ϕ • The Component I rms sinϕ is normal to E rms. Herethe phase angle between I rms sinϕ and E rmsis π/2. P av= E rms(I rmssin ϕ) \(\cos \frac\)= 0 • We call the component I rms sin ϕas the idle or wattles currentbecause it does not consume any power in a.c. circuit. This happens in a purely inductive or capacitive circuit in which current and voltage differ by a phase difference of π /2. • Hence option 2 is correct. NOTE: • The wattless currentis possible in a circuit where resistance is zero.

The correct option is D 1000 2 , 10 Explanation for correct option: Step 1: Given data The instantaneous e.m.f. is, e = 100 sin 30 t the instantaneous current is, i = 20 sin 30 t - π 4 We have to find the average power consumed and wattless current in one cycle. Step 2: Formula to be used In an AC circuit, the average power is determined by using root mean square current rms values of emf and current. When the average power consumed by an AC circuit is equal to zero, wattless current is the amount of current that is flowing. The rms value of the current can be used to calculate it. The average power consumed by an A . C . circuit is, P avg = e rms I rms cosϕ Here, e rms is the average value of e.m.f. in the A . C . circuit, I rms is the average value in the A . C . and ϕ is the phase constant. Wattless current is defined as the current in an A . C . circuit when the average power consumed by the A . C . circuit is equal to zero. The wattles current is, I = I rms sinϕ Here, I is the wattles current, I rms is the average value of current in an A . C . circuit, and ϕ is the phase constant. Step 3: Set the value of I rms and e rms, The values of instantaneous emf and current is given as, e = 100 sin 30 t ------- 1 i = 20 sin 30 t - π 4 ------- 2 So, these above two equations are in the form of wave equations due to dealing with alternating current and voltage. From these wave equations, the maximum values of emf and current in the given A . C . circuit is 100 and 20, res...