Home
Class 12
PHYSICS
Assertion : We use a thick wire in the s...

Assertion : We use a thick wire in the secondary of a step down transformer to reduce the production heat .
Reason : When the plane of the armature is parallel to the lines of force of magnetic field , the magnitude of induced e.m.f. is maximum .

A

If the Assertion & Reason are True & the Reason is a correct explanation of the Assertion .

B

If both Assertion & Reason are True & the Reason is not a correct explanation of the Assertion.

C

If Assertion is True but the Reason is Fasle.

D

If both Assertion and Reason are False .

Text Solution

Verified by Experts

The correct Answer is:
b
Promotional Banner

Topper's Solved these Questions

  • ELECTRO MAGNETIC INDUCTION

    MOTION|Exercise EXERCISE-4| Section A (Prevous Years Problems )|28 Videos

  • ELECTRO MAGNETIC INDUCTION

    MOTION|Exercise EXERCISE-4| Section B (Prevous Years Problems )|29 Videos

  • ELECTRO MAGNETIC INDUCTION

    MOTION|Exercise EXERCISE-2 (Objective problems (Analytical questions))|70 Videos

  • Electrical Instrument

    MOTION|Exercise EXERCISE -3|16 Videos

  • ELECTRO MAGNETIC WAVES

    MOTION|Exercise EXERCISE - 3 (SECTION - B)|8 Videos

Similar Questions

Explore conceptually related problems

At which position of the plane of the rotating coil with the direction of magnetic field the e.m.f induced in the coil is maximum ?

Assertion A conducting loop is rotated in a uniform magnetic field with constant angular velocity omega as shown in figure. At time t = 0, plane of the loop is perpendicular to the magnetic field. Induced emf produced in the loop is maximum when plane of loop is parallel to magnetic field. Reason When plane of loop is parallel to magnetic field, then magnetic flux passing through the loop is zero.

A rectangular loop of wire is placed perpendicualr to a uniform magnetic field and then spun around one of its sides at frequency f. The induced emf is a maximum when the

Asseration:The induced e.m.f. and curent will be same in two identical loops of copper and aluminium, when rotated with same speed in the same magnetic field. Reason:Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire.

A metallic wire bent in the form of a semi-circle of radius 0.1 m is moved in a direction parallel to its plane, but perperdicular to a magnetic field B = 20 mT with a vel. Of 10 m//s . Find the e.m.f. induced in the wire.

A planar loop of wire rotates in a uniform magnetic field.Initially at t=0,the plane,of the loop is perpendicular to the magnetic field.If it rotates with a period of 10s, about an axis in its plane then,the magnitude of induced emf will be maximum and,minimum,respectively at-

A rectangular frame ABCD, made of a uniform metal wire, has a straight connection between E and F made of the samae wire, as shown in fig. AEFD is a square of side 1m, and EB=FC=0.5m. The entire circuit is placed in steadily increasing, uniform magnetic field directed into the plane of the paper and normal to it. The rate of change of the magnetic field is 1T//s . The resistance per unit length of the wire is 1omega//m . Find the magnitude and directions of the currents in the segments AE, BE and EF.

A coil formed by wrapping 50 turns of wire in the shape of a square is positioned in a magnetic field so that the normal to the plane of the coil makes an angle of 30^@ . with the direction of the field. When the magnetic field is increased uniformly from 200 muT to 600muT in 0.4 s , an emf of magnitude 80.0 mV is induced in the coil. What is the total length of the wire?

A square loop of side 10 cm and resistance 0.70 ohm is placed vertically in the east -west plane. A uniform magnetic field of 0.10 T is set up across the plane in north-east direction. The magnetic field is decreased to zero in 0.7 sec. at a steady rate. Determine the magnitudes of induced e.m.f. and current during this time interval.

In a trapeze-shaped structure, two rigid wires of negligble mass support a conducting bar of mass m and length L as shown in Fig. A source of emf is applied to the wires so that a current I flows through the bar. A uniform magnetic field vec B is perpendicular to the plane of the wires and bar. a. Compute the current that the source of emf must provide so that there is no tension in the wires. b. If the current is reduced to half the value computed in (a) and the plane of the structure is moved through an angle theta , compute the tension in the wires and the magnitude of the net unbalanced force on the bar at the instant it is released from this angle.

MOTION-ELECTRO MAGNETIC INDUCTION-EXERCISE-3 (Assertion & Reasoning)
  1. Assertion :- Whenever magnetic flux linked with the coil changes with ...

    Text Solution

    |

  2. Assertion :- Magnetic flux through the wood ring changes with respect ...

    Text Solution

    |

  3. Assertion :- When a bar magnet moves along the axis of conducting coil...

    Text Solution

    |

  4. Assertion :- If magnetic flux through any circuit is changes then an e...

    Text Solution

    |

  5. Assertion :- The mutual inductance M between two coils of self inducta...

    Text Solution

    |

  6. Assertion :- Voltage across L (see figure) at t=0 is E Reason:- Beca...

    Text Solution

    |

  7. Assertion :- At any instant , if the current through an inductor is ze...

    Text Solution

    |

  8. Assertion :- Due to high inductance of any coil the current attains it...

    Text Solution

    |

  9. Assertion :- A current is flowing through a coil with 5 volt battery ....

    Text Solution

    |

  10. Assertion :- Unlike charges are projected in opposite direction in tra...

    Text Solution

    |

  11. Assertion :- Faraday's copper disc generator is based on dynamic elect...

    Text Solution

    |

  12. Assertion :- When a conducting rod moves in uniform transverse magnet...

    Text Solution

    |

  13. Assertion :- If s steel core is used in a transformer in place of sof...

    Text Solution

    |

  14. Electromagnets are made of soft iron because soft iron has

    Text Solution

    |

  15. Assertion :- A thin aluminum disc, spinning freely about a central piv...

    Text Solution

    |

  16. Assertion : We use a thick wire in the secondary of a step down transf...

    Text Solution

    |

  17. Assertion: The quantity L//R possesses dimensions of time. Reason: T...

    Text Solution

    |

  18. Assertion : An emf vec(E) is induced in a closed loop where magnetic f...

    Text Solution

    |