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Magnetism And Matter — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsMagnetism And Matter1 Mark
Question
Two statements are given-one labelled Assertion(A) and the other labelled Reason (R). Select the correct answer to these questions from the codes(a), (b), (c) and (d) as given below.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is NOT the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): Earth's magnetic field does not affect the working of a moving coil galvanometer.
Reason (R): The earth's magnetic field is quite weak as compared to magnetic field produced in the moving coil galvanometer.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.

Explanation:

The field magnet used in a moving coil galvanometer is very strong. The earth's magnetic field is quite weak as compared to the magnetic field produced by the field magnet. Practically the coil rotates under the effect of the strong magnetic field due to the field magnet and the weak magnetic field due to the earth does not affect the working of the moving coil galvanometer.

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