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A loosely wound helix made of stiff meta...

A loosely wound helix made of stiff metal wire is mounted vertically with the lower end just touching the mercury in a dish. When the current from a battery is started in the metal wire through the mercury. then the spring

A

Executes oscillatory motion

B

Expands

C

contracts

D

none

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The correct Answer is:
A
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AAKASH SERIES-MOVING CHARGES AND MAGNETISM-EXERCISE-IA
  1. A square loop, carrying a steady current I, is placed in a horizontal ...

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  2. A long, straight wire carries a current along the z-axis. One can find...

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  3. A loosely wound helix made of stiff metal wire is mounted vertically w...

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  4. A current carrying loop in a uniform magnetic field will experience to...

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  5. Two very long, straight, parallel wires carry steady currents I and -I...

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  6. A rigid circular loop of radius r and mass m lies in the x-y plane...

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  7. A current carrying circular coil, suspended freely in a uniform extern...

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  8. A current loop in a magnetic field

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  9. A square loop ABCD, carrying a current I(2) is placed near and coplan...

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  10. In the above question, the acceleration of the rim will be?

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  11. A circular coil of n turns and area of crosssection A , carrying a cur...

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  12. A moving coil type of galvanometer is based upon the principle that a ...

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  13. The relation between voltage sensitivity (sigma(y)) and current sensit...

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  14. The best method to increase the sensitivity of a moving coil galvanome...

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  15. A conducting wire of given length is used to prepare the 'coil' of a m...

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  16. In a moving coil galvanometer a radial magnetic field is obtained with...

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  17. When a current is passed in moving coil galvanometer, the coil gets de...

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  18. The current that must flow through the coil of a galvanometre so as to...

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  19. To double the torque acting on a coil of n-turns, when placed in a mag...

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  20. A tangent galvanometer shows no deflection when a current is passed th...

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