Question

For an electrical project in a residence, the electrical engineer had resistors

Answer 1

Answer:

$ 0.077

Explanation:

We'll begin by calculating the equivalent resistance of the three 300 Ω resistors connected in series. This can be obtained as follow:

Equivalent resistance of the three 300 Ω (R₃₀₀) = 300 + 300 + 300

= 900 Ω

Next, we shall determine the equivalent resistance of the two 100 Ω resistors connected in series. This can be obtained as follow:

Equivalent resistance of the two 100 Ω (R₁₀₀) = 100 + 100

= 200 Ω

Next, we shall determine the equivalent resistance in the circuit. This can be obtained as follow:

Equivalent resistance of the three 300 Ω (R₃₀₀) = 900 Ω

Equivalent resistance of the two 100 Ω (R₁₀₀) = 200 Ω

Equivalent Resistance (R) =?

R = R₃₀₀ × R₁₀₀ / R₃₀₀ + R₁₀₀ (since they are in parallel connections)

R = 900 × 200 / 900 + 200

R = 163.64 Ω

Next, we shall determine the energy in KWh. This can be obtained as follow:

Voltage (V) = 10 V

Resistance (R) = 163.64 Ω

Time (t) for 30 days = 12 × 30 = 360 h

Energy (E) =?

E = V²t / R

E = 10² × 360 / 163.64

E = 100 × 360 / 163.64

E = 36000 / 163.64

E = 220 Wh

Divide by 1000 to express in KWh

E = 220 Wh / 1000 = 0.22 KWh

Finally, we shall determine the amount paid for 1 month (30 days). This can be obtained as follow:

Cost per KWh = $ 0.35

Energy (E) = 0.22 KWh

Cost for 30 days =?

Cost for 30 days = Energy × Cost per KWh

Cost for 30 days = 0.22 × 0.35

Cost for 30 days = $ 0.077

Therefore, the amount that must be paid for 1 month is $ 0.077