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  • Question
  • Assertion (A): Dielectric losses are proportional to tan ?.

    Reason (R): tan ? = Assertion (A): Dielectric losses are proportional to tan ?. Reason (R): tan ? = where ?r' and ?r where ?r' and ?r" denote the real and imaginary parts of ?r.


  • Options
  • A. Both A and R are true and R is correct explanation of A
  • B. Both A and R are true but R is not correct explanation of A
  • C. A is true but R is false
  • D. A is false but R is true

  • Correct Answer
  • Both A and R are true and R is correct explanation of A 


  • Materials and Components problems


    Search Results


    • 1. An electron shell corresponding to principal quantum number n can contain a maximum of

    • Options
    • A. n2 electrons
    • B. 2n2 electrons
    • C. 2n electron
    • D. n3 electron
    • Discuss
    • 2. In an hydrogen atom, an electron moves in the field of a proton. The stability of orbit requires equilibrium between coulomb's force and centrifugal force.

    • Options
    • A. True
    • B. False
    • Discuss
    • 3. A particle of charge Q coulombs is bound elastically to an equilibrium position with a force constant of f newton per metre. The polarizability of the system is

    • Options
    • A.
    • B.
    • C.
    • D. Qf
    • Discuss
    • 4. An homogeneous dielectric material is subjected to an electric field E. If a small cavity is made inside the material, the electric field intensity inside and outside the cavity are different.

    • Options
    • A. True
    • B. False
    • Discuss
    • 5. An electron in a homogeneous magnetic field and having velocity perpendicular to the direction of field moves

    • Options
    • A. perpendicular to the field
    • B. along the field
    • C. along a straight line inclined at 45° to field
    • D. in a circular path
    • Discuss
    • 6. Spontaneous polarization occurs in ferroelectric materials.

    • Options
    • A. True
    • B. False
    • Discuss
    • 7. For a core having a relative permeability ?r, magnetic dipole moment per unit volume M and field strength H, the flux density B is

    • Options
    • A. B = ?r (H + M)
    • B. B = ?0 (H + M)
    • C. B = ?0?r (H + M)
    • D. B = ?0?r (H - M)
    • Discuss
    • 8. Figure shows a composite capacitor. If CA, CB, CC are the capacitances of capacitors A, B, C, the overall capacitance C is

    • Options
    • A. C = CA + CB + CC
    • B. C = (CA + CB) CC
    • C. C =
    • D. C =
    • Discuss
    • 9. Assertion (A): In some materials, ?r is independent of temperature while in others, ?r depends on temperature.

      Reason (R): If permanent dipoles are absent, ?r varies with temperature.


    • Options
    • A. Both A and R are true and R is correct explanation of A
    • B. Both A and R are true but R is not correct explanation of A
    • C. A is true but R is false
    • D. A is false but R is true
    • Discuss
    • 10. The direction of force an a conductor carrying current and lying in a magnetic field can be found by using

    • Options
    • A. Fleming's left hand rule
    • B. Fleming's right hand rule
    • C. Cork screw rule
    • D. Any of the above
    • Discuss


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