What are the factors on which the power factor depends?

Important Questions on Transient Current and Alternating Current

EASY

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 32

Why a dc voltmeter and a dc ammeter cannot read ac?

EASY

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 33

Define the mean value of an alternating current.

MEDIUM

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 34

The given graph of Fig. $10.59$ (a)  and (b) represent the variation of the opposition offered by the circuit element to the flow of alternating current with frequency of the applied emf. Identify the circuit element corresponding to

MEDIUM

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 35

What is the power dissipated in an ac circuit in which voltage and current are given by $V=250\sin \left(\omega t+\frac{\pi }{2}\right)$ and $I=10\sin \omega t.$

EASY

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 36

The power factor of an ac circuit is $0.5$. What will be the phase difference between the voltage and current in this circuit?

EASY

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 37

Can the voltage drop across the inductor or the capacitor in a series $LCR$ circuit be greater than the applied voltage of an ac source? Justify your answer.

MEDIUM

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 38

At resonance what is the value of power factor in the case of $LCR$ series circuit? 

EASY

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 10 - Transient Current and Alternating Current>EXERCISE 10>Q 39

An electrical element $X,$ when connected to an alternating voltage source, has the current through it leading the voltage by $\pi /2$ radian. Identify X and write an expression for its reactance.