Start learning →

Bihar Board Class 12 (Science) Electromagnetic Induction & Alternating Current — practice questions — page 3

Explore 78 free Electromagnetic Induction & Alternating Current questions in Bihar Board Class 12 (Science) Physics. Open each question or exercise to read its content, reference answers and available explanation.

Practise Electromagnetic Induction & Alternating Current with Quill →

Electromagnetic Induction & Alternating Current questions and exercises with answers

Showing questions 61–78 of 78.

Alternating voltages are stepped up or down by means of:Read the answer and worked solution →The rms current equals the dc current that would produce the same:Read the answer and worked solution →At resonance in a series LCR circuit, the impedance is:Read the answer and worked solution →At resonance the current amplitude in the circuit is:Read the answer and worked solution →Besides an inductor, resonance needs the circuit to contain a:Read the answer and worked solution →The quantity cos of the phase angle is called the:Read the answer and worked solution →A current that dissipates no power is referred to as:Read the answer and worked solution →Maximum power is dissipated in a series LCR circuit at:Read the answer and worked solution →Inductive reactance is directly proportional to the:Read the answer and worked solution →A radio is tuned to a station by matching the resonant frequency of:Read the answer and worked solution →Resonance is described as a phenomenon that is:Read the answer and worked solution →The impedance of a series LCR circuit at resonance equals:Read the answer and worked solution →A lagging wattless current is neutralised by adding an equal:Read the answer and worked solution →The SI unit of inductance is the:Read the answer and worked solution →The emf Blv produced by a moving conductor is called:Read the answer and worked solution →The SI unit of reactance is the:Read the answer and worked solution →At the resonant frequency, the two reactances are:Read the answer and worked solution →Lenz's law fixes which feature of the induced emf?Read the answer and worked solution →

Worked practice questions

Alternating voltages are stepped up or down by means of:

  1. Capacitors
  2. Resistances
  3. Transformers
  4. Rectifiers
Show answer and solution

Correct answer: C. Transformers

1. Direct voltages cannot be changed this simply. 2. Alternating voltages can, which is why ac is used for supply. 3. The device that does it is the transformer. 4. So the answer is transformers. _Source: syllabus Physics, Ch 7 'Alternating Current'_

Open this question →

The rms current equals the dc current that would produce the same:

  1. Peak voltage
  2. Phase angle
  3. Time period
  4. Heating effect
Show answer and solution

Correct answer: D. Heating effect

1. The rms value is defined to make ac and dc comparable. 2. The comparison is made through the power dissipated. 3. It is the equivalent dc current giving the same heating. 4. So the answer is heating effect. _Source: syllabus Physics, Ch 7 'Alternating Current'_

Open this question →

At resonance in a series LCR circuit, the impedance is:

  1. Minimum
  2. Maximum
  3. Infinite
  4. Negative
Show answer and solution

Correct answer: A. Minimum

1. At resonance the two reactances become equal. 2. They cancel, leaving only the resistance. 3. So the impedance falls to its minimum value R. 4. The answer is minimum. _Source: syllabus Physics, Ch 7 'Alternating Current'_

Open this question →

How to practise

  1. Choose a Electromagnetic Induction & Alternating Current question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

Put it into practice

Continue with Electromagnetic Induction & Alternating Current practice for Bihar Board Class 12 (Science). Read explanations as you go. No signup form needed to start.

Practise Electromagnetic Induction & Alternating Current →

More Physics topics

Moving Charges and MagnetismRay Optics and Optical InstrumentsSemiconductor ElectronicsCurrent ElectricityElectric Charges and FieldsDual Nature of Radiation and MatterWave OpticsAtoms and Nuclei