Student Login

Home›Chapters›Alternating Current PYQs›Power, Power Factor & Wattless Current›Question 69

NEET 2015 (AIPMT, Cancelled Paper) · Power, Power Factor & Wattless Current

Power, Power Factor & Wattless Current question from NEET 2015 (AIPMT, Cancelled Paper)

Q69NEET 2015 · AIPMT · CANCELLED PAPERMedium

Power, Power Factor & Wattless Current

A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z'. the power drawn will be

Show answer and solution

Answer: (c)

With $R$ alone: $P = \frac{V^2}{R}$ .
With $L$ added: $P' = I^2R = \frac{V^2}{Z^2}R$ .
$P' = \frac{V^2}{R} \cdot \frac{R^2}{Z^2} = P\left(\frac{R}{Z}\right)^2$ .
So the answer is (c) $P\left(\frac{R}{Z}\right)^2$ .

Report a mistake

More questions on Power, Power Factor & Wattless Current

For the LCR circuit, shown here, the current is observed to lead the applied voltage. An…JEE Main 2015 (11 Apr, Shift 1)
A series LR circuit is connected to an ac source of frequency ω and the inductive…JEE Main 2013 (25 Apr, Shift 1)
The instantaneous values of alternating current and voltage in a circuit are given as i =…NEET 2012 (AIPMT, Mains)
In a series LCR circuit R = 200 Ω and the voltage and the frequency of the main supply…JEE Main 2010 (AIEEE)
Power dissipated in an LCR series circuit connected to an A.C. source of emf ε isNEET 2009 (AIPMT)
In an a.c. circuit the e.m.f. ( ε) and the current (i) at any instant are given…NEET 2008 (AIPMT)
In an a.c. circuit the voltage applied is E = E₀sin ω t. The resulting current in the…JEE Main 2007 (AIEEE)
A coil of inductive reactance 31 Ω has a resistance of 8 Ω. It is placed in series with a…NEET 2006 (AIPMT)