Philippine Electrical Code (Subject 2) - Nth

1.The circuit in the figure shows the resistors R2 and R3 connected in parallel, but resistor R1 is in series with both the battery and the parallel combination of R2 and R3. What is the total resistance of R2 and R3?

• 40 ohms

• 10 ohms

• 20 ohms

• 30 ohms

2. If the total combined resistance of R2 and R3 is 10 ohms, what is the total resistance of the entire circuit in figure?

• 15 ohms

• 20 ohms

• 45 ohms

• 5 ohms

3. Assuming the battery in the figure is 30 volts, what is the total current in the circuit?

• 1 ampere

• 2 amperes

• 3 amperes

• 4 amperes

4. According to Kirchhoff’s voltage law, which of the following Ohm’s law equations may be used to find the voltage drop across a resistor?

• Voltage drop = IR

• Voltage drop = I/R

• Voltage drop = E/R

• Voltage drop = W/I

5. A 120-volt circuit has an electric heater connected with a current rating of 7.5 amperes. What is the resistance in ohms of the connected pure resistance load?

• 8 ohms

• 10 ohms

• 16 ohms

• 20 ohms

What current is drawn by a 277-volt fluorescent lamp with 8 ohms resistance?

• 20.52 amperes

• 60.75 amperes

• 34.62 amperes

• 10.30 amperes

7. If the impedance Z of the circuit impedance triangle in the figure

is 5 ohms and angle A is 30°, what is the value of the inductive reactance (XL)?

• 2.5 ohms

• 6.75 ohms

• 3.2 ohms

• 12.3 ohms

8. What is the minimum general lighting load permitted by the NEC in a 4500 square foot warehouse?

• 1005 volt-amperes

• 1125 volt-amperes

• 1750 volt-amperes

• 1243 volt-amperes

9. What is the minimum general lighting load permitted in a 1500 square foot single-family dwelling as specified in Table 220.12 of the NEC?

• 4500 volt-amperes

• 3500 volt-amperes

• 7350 volt-amperes

• 2130 volt-amperes

10. The voltage per turn for a transformer is 1.25 volts. What is the voltage of the transformer if it has 192 turns?

• 12 volts

• 240 volts

• 120 volts

• 24 volts