Download Aptitude Crack
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Materials and Components - Engineering

Q1:

Assertion (A): In a perfect capacitor, the current density is given by ω ∈0E0∈'rcos(ωt + 90°), where ∈r' is real part of dielectric constant. Reason (R): In a perfect capacitor, dielectric losses are zero.

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

ANS:A - Both A and R are true and R is correct explanation of A

If dielectric losses are zero, the current in capacitor leads the applied voltage by 90°. Also imaginary part of is ∈r is zero.