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

• Both A and R are true and R is correct explanation of A
• Both A and R are true but R is not correct explanation of A
• A is true but R is false
• A is false but R is true