ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Generated EMF of a DC generator is 220 V at 1000 rpm. At 1500 rpm, EMF is:
A)
220 V
B)
300 V
C)
330 V
D)
440 V
For a DC generator at constant flux, generated EMF is proportional to speed: 220 × 1500/1000 = 330 V.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Which conductor is commonly used in H.T. transmission lines?
A)
Copper only
B)
Iron
C)
Aluminum (ACSR)
D)
Steel
Correct answer: C — Aluminum (ACSR)
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Soft starter is used to:
A)
Increase speed instantly
B)
Reduce starting current and torque
C)
Increase voltage
D)
Store energy
Option C is correct: Increase voltage.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Circuit breaker is used to:
A)
Measure current
B)
Isolate faulty current
C)
Increase voltage
D)
Store energy
Correct answer: B — Isolate faulty current
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
The number of poles affects:
A)
Voltage only
B)
Current only
C)
Speed of machine
D)
Resistance
Correct answer: C — Speed of machine
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Interlocking in control circuits is used to:
A)
Increase voltage
B)
Reduce current
C)
Prevent simultaneous operation of conflicting circuits
D)
Store energy
Option C is correct: Prevent simultaneous operation of conflicting circuits.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Commutator is used in DC machines to:
A)
Increase voltage
B)
Convert AC to DC
C)
Store energy
D)
Reduce speed
Correct answer: B — Convert AC to DC
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Which material is commonly used for winding?
A)
Iron
B)
Steel
C)
Copper
D)
Silver
Correct answer: C — Copper
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
DC motor speed control can be done by:
A)
Relay control
B)
Armature voltage control
C)
Transformer
D)
Relay
Option B is correct: Armature voltage control.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Short pitch winding is used to:
A)
Increase harmonics
B)
Increase voltage
C)
Reduce harmonics
D)
Increase resistance
Correct answer: C — Reduce harmonics
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Low resistivity metals are used to:
A)
Increase voltage
B)
Decrease voltage
C)
Stop leakage current
D)
Conduct current
Correct answer: D — Conduct current
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Which insulation class has highest temperature rating?
A)
Class A
B)
Class B
C)
Class F
D)
Class H
Correct answer: D — Class H
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Transformer core is made of:
A)
Copper
B)
Aluminum
C)
Laminated silicon steel
D)
Iron rod
Correct answer: C — Laminated silicon steel
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Efficiency of transformer is maximum when:
A)
No load
B)
Full load
C)
Copper loss = Iron loss
D)
Voltage is zero
Option A is correct: No load.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
In parallel operation of transformers, it is necessary that there should be:
A)
Different voltage ratios
B)
Same polarity and voltage ratio
C)
Different frequency
D)
Different core material
Option C is correct: Different frequency.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
For a 6-pole, 50 Hz motor, synchronous speed is:
A)
1250 rpm
B)
1000 rpm
C)
1500 rpm
D)
3000 rpm
Synchronous speed = 120f/P = 120×50/6 = 1000 rpm.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
IGBT stands for:
A)
Integrated Gate Bipolar Transistor
B)
Insulated Gate Bipolar Transistor
C)
Internal Gate Base Transistor
D)
Input Gate Bipolar Transistor
Option C is correct: Internal Gate Base Transistor.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Frequency of AC generator depends on:
A)
Voltage
B)
Current
C)
Speed and number of poles
D)
Resistance
Correct answer: C — Speed and number of poles
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Number of parallel paths in lap winding is equal to:
A)
2
B)
Number of poles
C)
Number of coils
D)
1
For a simplex lap winding, the number of parallel paths equals the number of poles.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
If slip is 5% and synchronous speed is 1500 rpm, rotor speed is:
A)
1500 rpm
B)
1450 rpm
C)
1425 rpm
D)
1400 rpm
Rotor speed = synchronous speed × (1 − slip) = 1500 × 0.95 = 1425 rpm.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
If frequency is reduced from 50 Hz to 25 Hz, synchronous speed becomes:
A)
Same
B)
Double
C)
Half
D)
Zero
Correct answer: C — Half
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Speed control of DC motor can be done by:
A)
Resistance only
B)
Voltage only
C)
Flux and armature voltage control
D)
Frequency only
Correct answer: C — Flux and armature voltage control
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Which accessory is used for protection in control circuits?
A)
Lamp
B)
Fuse/MCB
C)
Switch
D)
Socket
Option A is correct: Lamp.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
Control circuits usually operate at:
A)
High voltage
B)
Low voltage
C)
Zero voltage
D)
Variable voltage
Option C is correct: Zero voltage.
ITI Instructor • 2026 • Paper-IV (Electrician - Technical Paper-II)
A motor draws 50 A without starter and 10 A with starter. Reduction is:
A)
20%
B)
40%
C)
80%
D)
50%
Current falls from 50 A to 10 A, a reduction of 40/50 = 80%.
