Esco Electrical Test
1. A ___ is commonly used on a single phase fractional horsepower
compressor to disconnect the start winding.
● A. Voltage relay
● B. Time delay relay
● C. Pressure relay
● D. Current relay
Answer: D. Current relay
2. A capacitor analyzer is designed to check:
● A. Voltage
● B. Current
● C. Resistance
● D. The capacitance of a capacitor
Answer: D. The capacitance of a capacitor
3. A device with overload protection used to control a motor is a:
● A. Contactor
● B. Relay
● C. Circuit breaker
● D. Line starter
Answer: D. Line starter
4. A diode is used to:
● A. Control the direction of electron flow
● B. Increase voltage
● C. Store energy
● D. Create resistance
Answer: A. Control the direction of electron flow
,5. A parallel circuit consists of three resistors; R1 = 30 ohms, R2 = 15 ohms,
R3 = 10 ohms. If the current through R2 = 4 amps, what is the source voltage?
● A. 30 volts
● B. 60 volts
● C. 120 volts
● D. 240 volts
Answer: B. 60 volts
6. A parallel circuit contains an 18 ohm and a 9 ohm resistor. What is the total
resistance?
● A. 6 ohms
● B. 9 ohms
● C. 18 ohms
● D. 27 ohms
Answer: A. 6 ohms
7. A solenoid valve operates on the principle of:
● A. Thermodynamics
● B. Hydraulics
● C. Electromagnetism
● D. Pneumatics
Answer: C. Electromagnetism
8. A step-up transformer increases:
● A. Current
● B. Voltage
● C. Resistance
● D. Power
Answer: B. Voltage
9. A thermocouple can:
, ● A. Measure pressure
● B. Control current
● C. Generate a small DC current
● D. Store electrical energy
Answer: C. Generate a small DC current
10. A three phase load requires a minimum of:
● A. Three supply lines
● B. Two supply lines
● C. Four supply lines
● D. One supply line
Answer: A. Three supply lines
11. A transformer has 1000 turns on the primary side and 2000 on the
secondary. What is the output if the input is 120v?
● A. 60v
● B. 120v
● C. 180v
● D. 240v
Answer: D. 240v
12. A transformer has 1000 turns on the primary side and 500 on the
secondary. What is the output if the input is 120v?
● A. 30v
● B. 45v
● C. 60v
● D. 120v
Answer: C. 60v
13. Amps can be calculated by:
● A. E/R
● B. W/E
1. A ___ is commonly used on a single phase fractional horsepower
compressor to disconnect the start winding.
● A. Voltage relay
● B. Time delay relay
● C. Pressure relay
● D. Current relay
Answer: D. Current relay
2. A capacitor analyzer is designed to check:
● A. Voltage
● B. Current
● C. Resistance
● D. The capacitance of a capacitor
Answer: D. The capacitance of a capacitor
3. A device with overload protection used to control a motor is a:
● A. Contactor
● B. Relay
● C. Circuit breaker
● D. Line starter
Answer: D. Line starter
4. A diode is used to:
● A. Control the direction of electron flow
● B. Increase voltage
● C. Store energy
● D. Create resistance
Answer: A. Control the direction of electron flow
,5. A parallel circuit consists of three resistors; R1 = 30 ohms, R2 = 15 ohms,
R3 = 10 ohms. If the current through R2 = 4 amps, what is the source voltage?
● A. 30 volts
● B. 60 volts
● C. 120 volts
● D. 240 volts
Answer: B. 60 volts
6. A parallel circuit contains an 18 ohm and a 9 ohm resistor. What is the total
resistance?
● A. 6 ohms
● B. 9 ohms
● C. 18 ohms
● D. 27 ohms
Answer: A. 6 ohms
7. A solenoid valve operates on the principle of:
● A. Thermodynamics
● B. Hydraulics
● C. Electromagnetism
● D. Pneumatics
Answer: C. Electromagnetism
8. A step-up transformer increases:
● A. Current
● B. Voltage
● C. Resistance
● D. Power
Answer: B. Voltage
9. A thermocouple can:
, ● A. Measure pressure
● B. Control current
● C. Generate a small DC current
● D. Store electrical energy
Answer: C. Generate a small DC current
10. A three phase load requires a minimum of:
● A. Three supply lines
● B. Two supply lines
● C. Four supply lines
● D. One supply line
Answer: A. Three supply lines
11. A transformer has 1000 turns on the primary side and 2000 on the
secondary. What is the output if the input is 120v?
● A. 60v
● B. 120v
● C. 180v
● D. 240v
Answer: D. 240v
12. A transformer has 1000 turns on the primary side and 500 on the
secondary. What is the output if the input is 120v?
● A. 30v
● B. 45v
● C. 60v
● D. 120v
Answer: C. 60v
13. Amps can be calculated by:
● A. E/R
● B. W/E
