AP EAMCET201823 Apr 2018Evening ShiftPhysicsMagnetic Effects of CurrentActual
A sample of a paramagnetic salt containing 3 10²⁴ atomic dipoles each of dipole moment 2 10⁻²³ ~A - m ^2 is subjected to a uniform magnetic field of 880 mT and cooled to a temperature of 3.5 ~K . The degree of magnetic saturation achieved is 10 % . If the sample is subjected to a magnetic field of 990 mT and cooled to a temperature of 2.1 ~K , then the total dipole moment of the sample is
Options
- A11.25 ~A - m ^2
- B23.5 ~A - m ^2
- C15 ~A - m ^2
- D75 ~A - m ^2
Correct answer
A. 11.25 ~A - m ^2
Step-by-step solution
Initially total dipole moment of sample =3 10²⁴ 2 10⁻²³ 10 100 =6 JT ⁻¹ From Curie's law, m B T , we get B₁ T₁ = B₂ T₂ or B₂=6 990 880 3.5 21 =11.25 ~A - m ^2