Electrical Circuit Design
Q1. What is the primary purpose of using a star-delta starter for a 3-phase induction motor?
a. To increase the starting torque
b. To reduce the starting current
c. To decrease the running speed
d. To provide backup power
Q2. Describe the difference between star and delta configurations in an induction motor.
a. Star configuration connects windings in series; delta configuration connects windings in parallel
b. Star configuration is used for high voltage; delta configuration is used for low voltage
c. Star configuration reduces voltage and current during start-up; delta configuration provides full voltage and current during normal operation
d. Star configuration is for single-phase motors; delta configuration is for three-phase motors
Q3. What are the key components of a star-delta starter circuit?
a. Only main contactor
b. Main contactor, star contactor, and delta contactor
c. Timer and overload relay
d. Start and stop buttons
Q4. Explain the function of the main contactor in a star-delta starter.
a. It connects the motor windings in star configuration
b. It disconnects the motor from the power supply
c. It connects the motor to the power supply
d. It protects the motor from overload
Q5. What is the role of the timer in a star-delta starter?
a. To delay the start of the motor
b. To control the duration of the star configuration before switching to delta configuration
c. To measure the running time of the motor
d. To protect the motor from overcurrent
