1. A series circuit consisting of three resistors has a current of 3 amps, R1 =12kohtms. R2 = 60 ohms, R3= 80 ohms and the power dissipation of 180W, what is:
a. Total resistance,
b. Source voltage of the circuit,
C . Power dissipation in each resistor of the circuit?
d. Voltage dropped in each resistor of the circuit?
e. If the current was increased to 4 amps, what would be voltage drop across each resistor?
f. What would have to be done to the circuit if the current increase to 4amps?
2.Four resistors are connected in parallel; R1 = 10 Ω. R 2 = 3KΩ , R3 = 1.5K Ω and R 4 = 560 Ω with the potential difference of 120v respectively, what is the equivalent resistance and IT and PT
3. Explain the following terms with their correct circuit diagram, formula and graph:
4. Explain the following terms with their correct circuit diagram, formula and graph:
a. What is AC circuit and what is the d/c b/n AC & DC?
b. Inductance in an AC circuit
c. Capacitance in an AC circuit
d. Resistance in an AC circuit
e. What is impedance? and
f. What is LCR?
5. The following a series RLC circuit with R = 3k ohm, L = 10H and C = 200uF has a constant voltage source V = 5theta*V AC signal with a frequency of 60 Hz.
a. Calculate the capacitive reactance and the inductive reactance in the circuit?
b. Determine the impedance?
C. Calculate the rms consumed in the circuit?
d. Calculate the voltage across the resistor, the inductor and the capacitor?
e. How much power is consumed in the circuit?
f. What is the resonant frequency of the circuit?
a. Total resistance = R1 + R2 + R3 = 12kΩ + 60Ω + 80Ω = 12.14kΩ
b. Source voltage = Current * Total resistance = 3A * 12.14kΩ = 36.42V
c. Power dissipation in each resistor:
- For R1: P1 = I^2 * R1 = 3^2 * 12kΩ = 108W
- For R2: P2 = I^2 * R2 = 3^2 * 60Ω = 540W
- For R3: P3 = I^2 * R3 = 3^2 * 80Ω = 720W
d. Voltage dropped in each resistor:
- For R1: V1 = I * R1 = 3A * 12kΩ = 36V
- For R2: V2 = I * R2 = 3A * 60Ω = 180V
- For R3: V3 = I * R3 = 3A * 80Ω = 240V
e. If the current is increased to 4A, the voltage drop across each resistor would be:
- For R1: V1 = 4A * 12kΩ = 48V
- For R2: V2 = 4A * 60Ω = 240V
- For R3: V3 = 4A * 80Ω = 320V
f. To accommodate the increased current of 4A, the resistors in the circuit may need to be replaced with higher power rated resistors to prevent overheating and potential damage.
g. Equivalent resistance (Req) of resistors in parallel can be calculated as:
1/Req = 1/R1 + 1/R2 + 1/R3 + 1/R4
= 1/10Ω + 1/3kΩ + 1/1.5kΩ + 1/560Ω
Req = 6.078Ω
h. Total current (IT) in the parallel circuit:
IT = V / Req
IT = 120V / 6.078Ω
IT = 19.72A
i. Total power (PT) dissipated in the parallel circuit:
PT = V * IT
PT = 120V * 19.72A
PT = 2366.4W
j. AC circuit: An alternating current (AC) circuit is a circuit where the current changes direction periodically. The primary difference between AC and DC is that in AC, the current changes direction, while in DC, the current flows in one direction.
k. Inductance in an AC circuit: Inductance is the property of an electrical circuit by which a voltage is induced by a changing current or by a current in a neighboring circuit.
l. Capacitance in an AC circuit: Capacitance is the ability of a system to store an electric charge.
m. Resistance in an AC circuit: Resistance in an AC circuit dissipates energy in the form of heat.
n. Impedance: It is the total opposition a circuit offers to the flow of current when alternating current is applied.
o. LCR circuit: An LCR circuit is a circuit that contains inductance (L), capacitance (C), and resistance (R) elements. The behavior of an LCR circuit depends on the values of these elements and their configuration.
p. Resonant frequency of the circuit can be calculated using the formula:
f = 1 / (2π * sqrt(L * C))
f = 1 / (6.28 * sqrt(10H * 200uF))
f = 1 / (6.28 * sqrt(0.002F))
f = 1 / (6.28 * 0.045)
f = 1 / 0.282
f ≈ 3.546Hz