ECEG 1551
1
ECEG 1551 INDIVIDUAL ASSIGNMENT 2
1. When
ωtcos42.4264(t)i
andωtsin56.5685(t)i
2
1
=
=
find i
1
(t) + i
2
(t).
2. A coil has R = 8Ω and L = 15.915mH. What is its impedance at 50 Hz.?
3. An RC circuit has R = 10Ω and C = 100μF. What is its impedance at 50
Hz.?
4. When a voltage of 50V a.c. supply is applied to a coil, it draws 10A and
dissipates 300W. Find the resistance and the inductive reactance of the
coil.
5. A voltage of
ωtsin300v(t) =
is applied to a circuit. The circuit takes a
current of
)( 0
60-ωtsin10i(t) =
. Determine the average power
consumed by the circuit.
6. When a voltage of 200
0
0
V is applied to a circuit, the current taken by
the circuit is
0
53.135 −
A. Compute the average power supplied by the
mains. Also determine the apparent power and the reactive power.
7. An inductive load of (5 + j12) Ω is connected to a 221V, 50Hz supply for
8 hours in a day. Find the energy consumed by the load in 20 days.
8. An inductive load takes 1.4kW at a p.f. of 0.8 from 220V, 50Hz supply. To
improve the circuit power factor to 0.9 lagging, a capacitor is connected
across the load, Find the value of the capacitor. Draw the phasors
diagram.
