Basic Electrical Engineering (3110005)

Question-3b

BE | Semester-1 Winter-2019 | 11-01-2020

Q3) (b)

From Eq. ( 1 )

V = \sqrt{{V_{R}}^{2} + {V_{L}}^{2}}

V = \sqrt{{(IR)}^{2} + {({IX}_{L})}^{2}}

V = I \sqrt{R^{2} + {X_{L}}^{2}}

V = I Z

Where,

Z = \sqrt{R^{2} + {X_{L}}^{2}}

From Eq. ( 2 )

Z = \sqrt{R^{2} + {X_{L}}^{2}}

ϕ = \tan^{- 1} (\frac{X_{L}}{R})

From Eq. ( 3 ) $Q = V I \sin ϕ = I^{2} X_{L}$

Real Power,

P = V I \cos ϕ = I^{2} R

Reactive Power,

Q = V I \sin ϕ = I^{2} X_{L}

Apparant Power,

S = V I = I^{2} Z