CITY & GUILDS 2365 UNIT 614
ADVANCED SCIENCE AND PRINCIPLES
PREP 2026/2027 | QUESTIONS AND
ANSWERS |2026/2027 UPDATE | JUST
RELEASED
1. A series circuit consists of a 40-ohm resistor and a 30-ohm inductive reactance. What is the
total impedance (Z) of the circuit?
A. 70 ohms
B. 10 ohms
C. 50 ohms
D. 1200 ohms
Answer: C
Conceptual Explanation: Using the Pythagorean theorem for impedance: Z = sqrt(R^2 +
XL^2) = sqrt(40^2 + 30^2) = sqrt(1600 + 900) = sqrt(2500) = 50 ohms.
2. In a balanced three-phase delta-connected system, what is the relationship between line
current (IL) and phase current (IP)?
A. IL = sqrt(3) x IP
B. IL = IP / sqrt(3)
,C. IL = IP
D. IL = 3 x IP
Answer: A
Conceptual Explanation: In a delta connection, the line current is root 3 times larger than
the phase current, whereas line voltage equals phase voltage.
3. A 4-pole induction motor is connected to a 50Hz supply. What is its synchronous speed in
revolutions per minute (rpm)?
A. 3000 rpm
B. 1500 rpm
C. 1000 rpm
D. 750 rpm
Answer: B
Conceptual Explanation: Synchronous speed Ns = (120 x f) / P. Here, (120 x 50) / 4 =
= 1500 rpm.
4. What is the primary cause of eddy current losses in a transformer core?
A. Resistance of the copper windings
B. Circulating currents induced in the conductive core material
C. The constant reversal of magnetic domains
, D. Poor insulation between the primary and secondary coils
Answer: B
Conceptual Explanation: Eddy currents are small loops of electric current induced within
conductors by a changing magnetic field in the core, causing heat loss.
5. An AC circuit has a real power of 8kW and an apparent power of 10kVA. What is the power
factor?
A. 0.8
B. 1.25
C. 0.6
D. 0.75
Answer: A
Conceptual Explanation: Power Factor = True Power (kW) / Apparent Power (kVA). 8 /
10 = 0.8.
6. Which component is primarily used to improve the power factor of an inductive load?
A. Resistor
B. Capacitor
C. Inductor
D. Transistor
ADVANCED SCIENCE AND PRINCIPLES
PREP 2026/2027 | QUESTIONS AND
ANSWERS |2026/2027 UPDATE | JUST
RELEASED
1. A series circuit consists of a 40-ohm resistor and a 30-ohm inductive reactance. What is the
total impedance (Z) of the circuit?
A. 70 ohms
B. 10 ohms
C. 50 ohms
D. 1200 ohms
Answer: C
Conceptual Explanation: Using the Pythagorean theorem for impedance: Z = sqrt(R^2 +
XL^2) = sqrt(40^2 + 30^2) = sqrt(1600 + 900) = sqrt(2500) = 50 ohms.
2. In a balanced three-phase delta-connected system, what is the relationship between line
current (IL) and phase current (IP)?
A. IL = sqrt(3) x IP
B. IL = IP / sqrt(3)
,C. IL = IP
D. IL = 3 x IP
Answer: A
Conceptual Explanation: In a delta connection, the line current is root 3 times larger than
the phase current, whereas line voltage equals phase voltage.
3. A 4-pole induction motor is connected to a 50Hz supply. What is its synchronous speed in
revolutions per minute (rpm)?
A. 3000 rpm
B. 1500 rpm
C. 1000 rpm
D. 750 rpm
Answer: B
Conceptual Explanation: Synchronous speed Ns = (120 x f) / P. Here, (120 x 50) / 4 =
= 1500 rpm.
4. What is the primary cause of eddy current losses in a transformer core?
A. Resistance of the copper windings
B. Circulating currents induced in the conductive core material
C. The constant reversal of magnetic domains
, D. Poor insulation between the primary and secondary coils
Answer: B
Conceptual Explanation: Eddy currents are small loops of electric current induced within
conductors by a changing magnetic field in the core, causing heat loss.
5. An AC circuit has a real power of 8kW and an apparent power of 10kVA. What is the power
factor?
A. 0.8
B. 1.25
C. 0.6
D. 0.75
Answer: A
Conceptual Explanation: Power Factor = True Power (kW) / Apparent Power (kVA). 8 /
10 = 0.8.
6. Which component is primarily used to improve the power factor of an inductive load?
A. Resistor
B. Capacitor
C. Inductor
D. Transistor
