NTDC Junior Engineer Electrical Paper 31 December 2022

Q1: The insulation strength of a high voltage transmission line is determined by

ایک ہائی وولٹیج ٹرانسمیشن لائن کی موصلیت کی طاقت کا تعین کیا جاتا ہے

Harmonics

Corona

Power factor

Switching over voltage

Q2: The power factor is said to be leading when

کہا جاتا ہے کہ پاور فیکٹر جب لیڈ ہوتا ہے۔

The current leads the voltage

The current lags the voltage

The voltage leads the current

voltage is in phase with the current

Q3: __ are used to sense the fault and initiate a trip

Circuit breakers

Alternators

Protective relays

Cut outs

Q4: The precision of an instrument is determined by the

Closeness of measurement with the true value

Closeness of measurement with the fixed value

Closeness of different measurement with the same quantity

None of these

Q5: For rectification, we use ___ as a rectifier .

Capacitor

Inductor

Diode

Resistor

Q6: The pressure in the working fluid cycle of a thermal power plant is developed by

تھرمل پاور پلانٹ کے کام کرنے والے سیال سائیکل میں دباؤ کی طرف سے تیار کیا جاتا ہے

Condenser

Feedwater pump

Super heater

turbine

Q7: Power plants using coal work closely on which of the following cycle ?

Otto cycle

Binary vapor cycle

Brayton cycle

Rankine cycle

Q8: The surge impedance of a long power transmission is of the order of

400

500

80

40

Q9: The electrical length of a transmission line is based on the

Physical length of the line

Wavelength of the AC on the line

Nominal voltage of the line

None of these

Q10: Skin effect is proportional to which of the following ?

Diameter of conductor

(Diameter of conductor )2

(Diameter of conductor )3

(Diameter of conductor )4