12th Class Physics Alternating Current / प्रत्यावर्ती धारा Question Bank

done Assertion And Reason (MCQs) - Alternating Current Total Questions - 35

• question_answer1)

  Directions : (1-35) For Assertion and Reason Type Questions

  In this type of question, a statement of assertion [A] is followed by a statement of reason [R]. Mark the correct choice as :

  Assertion: Average value of A.C. over a complete cycle is always zero.

  Reason: Average value of A.C. is always defined over half cycle.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer2)

  Assertion: The dc and ac both can be measured by a hot wire instrument.

  Reason: The hot wire instrument is based on the principle of magnetic effect of current.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer3)

  Assertion: The divisions are equally marked on the scale of A.C. ammeter.

  Reason: Heat produced is directly proportional to the current.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer4)

  Assertion: An alternating current does not show any magnetic effect.

  Reason: Alternating current varies with time.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer5)

  Assertion: The alternating current lags behind the e.m.f. by a phase angle of \[\frac{\pi }{2}\], when A.C. flows through an inductor.

  Reason: The inductive reactance increases as the frequency of A.C. source decreases.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer6)

  Assertion: A.C. is more dangerous than D.C.

  Reason: Frequency of A.C. is dangerous for human body.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer7)

  Assertion: Capacitors serves as a block for D.C. and offers an easy path to A.C.

  Reason: Capacitance reactance is inversely proportional to frequency.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer8)

  Assertion: A capacitor of suitable capacitance can be used in an A.C. circuit in place of the choke coil.

  Reason: A capacitor blocks D.C. and allows A.C. only.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer9)

  Assertion: When capacitive reactance is smaller than the inductive reactance in LCR series, e.m.f. leads the current.

  Reason: The phase angle is the angle between the alternating e.m.f. and alternating current of the circuit.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer10)

  Assertion: An inductance and a resistance are connected in series with an A.C. circuit. In this circuit the current and the potential difference across the resistance lag behind potential difference across the inductance by an angle \[\frac{\pi }{2}\].

  Reason: In L-R circuit voltage leads the Current by phase angle which depends on the value of inductance and resistance both.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer11)

  Assertion: At resonance, LCR series circuit, have maximum current.

  Reason: At resonance, in LCR series circuit, the current and e.m.f. are in phase with each other.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer12)

  Assertion: An electric heater is heated first by direct and then by alternating currents. For both the currents, the potential difference across the ends of the heater is the same. The rate of production of heat will be different in two cases.

  Reason: The resistance of a coil in alternating current will be more than the resistance of a coil in direct current, hence heat produced in case of direct current will be low.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer13)

  Assertion: When A.C. contains resistor only, its power is minimum.

  Reason: Power of a circuit is independent of phase angle.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer14)

  Assertion: The resistance of a coil for direct current is 5 ohms. An alternating current is sent, through it. The resistance will remain same.

  Reason: The resistance of a coil dos not depend upon nature of current.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer15)

  Assertion: An electric lamp connected in series with a variable capacitor and A.C. source, its brightness increases with increase in capacitance.

  Reason: Capacitive reactance decreases with increase in capacitance of capacitor.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer16)

  Assertion: When a current flows in the coil of a transformer then its core becomes hot.

  Reason: The core of transformer is made of iron.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer17)

  Assertion: A transformer cannot work on D.C. supply.

  Reason: D.C. changes neither in magnitude nor in direction.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer18)

  Assertion: An alternating current shows magnetic effect.

  Reason: Magnitude of alternating current varies with time.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer19)

  Assertion: An inductor acts as a perfect conductor for D.C.

  Reason: D.C. remains constant in magnitude and direction.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer20)

  Assertion: A bulb connected in series with a solenoid is connected to A.C. source. If a soft iron core is introduced in the solenoid, the bulb will glow brighter.

  Reason: On introducing soft iron Core in the solenoid, the inductance increases.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer21)

  Assertion: Step down transformer increases the current.

  Reason: Transformer obeys the law of conservation of energy.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer22)

  Assertion: If the frequency of alternating current in an A.C. circuit consisting inductance coil is increased then current gets decreased.

  Reason: The current is inversely proportional to frequency of alternating current.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer23)

  Assertion: Soft iron is used as a core of transformer.

  Reason: Area of hysteresis for soft iron is small.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer24)

  Assertion: The core of transformer is .made laminated in order to increase the eddy currents.

  Reason: The sensitivity of transformer increases with increase in the eddy currents.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer25)

  Assertion: Long disance transmission of A.C. is Carried out at extremely high voltage.

  Reason: For image distance, voltage has to be large.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion ad reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer26)

  Assertion: Principle of electromagnetic damping is used in dead beat galvanometer.

  Reason: To damp the oscillation metallic frame is used in the dead beat galvanometer.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer27)

  Assertion: Choke coil is preferred over a resistor to adjust in an A.C. circuit.

  Reason: Power factor for inductance is zero.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer28)
  Expected Questions

  Assertion: The quantity L/R possesses dimension of time.

  Reason: To reduce the rate of increase of current through a solenoid, we should we should increase the time constant \[\left( \frac{L}{R} \right)\].

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer29)

  Assertion: We use a thick wire in the secondary coil of a step down transformer to reduce the production of heat.

  Reason: When the plane of the armature is parallel to the line of force of magnetic field, the magnitude of induced e.m.f. is maximum.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer30)

  Assertion: Faraday's laws are consequences of conservation of energy.

  Reason: In a purely resistive A.C. circuit, the current lags behind the e.m.f.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer31)

  Assertion: No power loss associated with pure capacitor in a.c. circuit.

  Reason: No current is flowing in this circuit.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer32)

  Assertion: The alternating current lags behind the e.m.f. by a phase angle of \[\frac{\pi }{2}\], when AC flows through an inductor.

  Reason: The inductance reactance increases as the frequency of AC source decreases.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer33)

  Assertion: Inductance coils are usually made of thick copper wire.

  Reason: Induced current is more in wire having less resistance.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer34)

  Assertion: Transformers are used only in alternating current source not in direct current.

  Reason: Only A.C. can be stepped up or down by means by transfer.

   
  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow

• question_answer35)

  Assertion: At resonance, LCR series have a minimum current.

  Reason: At resonance, in LCR series circuit, the current and e.m.f. are not in phase with each other.

  A)
  If both assertion and reason are true and reason is the correct explanation of assertion. done clear
  B)
  If both assertion and reason are true and reason is not the correct explanation of assertion. done clear
  C)
  If assertion is true but reason is false. done clear
  D)
  If both assertion and reason are false. done clear
  E)
  If assertion is false but reason is true. done clear
  View Solution play_arrow