DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.2 A sinusoidal current is expressed as i(t) = 200 sin 200лt. The frequency of the signal is

1. 200 Hz
2. 50 Hz
3. 25 Hz
4. 100 Hz

Correct Option: 4

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.4 Find the average value of a full wave rectified alternation current having peak value of 100 A.

1. 7.07 A
2. 70.7 A
3. 63.7 A
4. 6.37 A

Correct Option: 3

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.5 Which of the following is an INCORRECT way of energy conservation in electric motors?

1. Reducing power factor
2. Optimum loading
3. Using soft starter
4. Improving power supply quality

Correct Option: 1

Q.6 A resistor absorbs an instantaneous power of (20 cost) mW when connected to a voltage source of v = 10 cost volts.
Find the value of the resistor.

1.50 £2
2.500 Ω
3. 5 kn
4. 50 kn

Correct Option: 3

Q.7 In a series RL circuit, the true power is equal to half the apparent power. Find the phase angle.

1. 30°
2. 90°
3. 60°
4. 45°

Correct Option: 3

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.9 With reference to corona effect, which of the following options is INCORRECT?

1. Radio interference
2. No power loss
3. Production of ozone
4. Hissing sound

Correct Option: 2

Q.10 Arrange the given materials in descending order according to their resistivity.
Silver, Mica, Silicon

1. Silver, Silicon, Mica
2. Mica, Silicon, Silver
3. Silicon, Mica, Silver
4. Mica, Silver, Silicon

Correct Option: 2

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.11 For producing 60 Hz frequency, a 24-pole alternator must run at

1. 1500 rpm
2. 600 rpm
3. 3000 rpm
4. 300 rpm

Correct Option: 4

Q.12 In a three-phase alternator, if the short pitch angle is ‘a’ degrees (electrical) for the fundamental flux wave, then pitch factor for 3rd harmonic will be:

1. Cos 30/2
2. Cos a/3
3. Cos a/2
4. 3*Cos a/2

Correct Option: 1

Q.13 With reference to underground cables, super tension cables are manufactured for operation in range.

1. 22 kV to 33 kV
2. 11 kV to 22 kV
3.33 kV to 66 kV
4.66 kV to 132 kV

Correct Option: 1

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q.17 Which condition is always correct for any transmission line?

1. AC-BD = 1
2. AB-CD=0
3. AB-CD=1
4. AD-BC1

Correct Option: 4

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

Q18. With reference to AC distribution, state whether the given statement are true or false.
Statements:

1. In AC system, the voltage drop is due to resistance only.
2. In AC system, the additions or subtractions of currents are done vectorially.
1. Statement 1 and 2 both are false
2. Statement 1 is false, but statement 2 is true
3. Statement 1 and 2 are both true
4. Statement 1 is true, but statement 2 is false

Correct Option: 2

Q.19 Among the generalised circuit constants of transmission line, constant B is expressed in

1. Ohms
2. Amperes
3. Volts
4. Siemens

Correct Option: 1

Q.20 For which of the following conditions does an induction machine act as a generator?

1. Slip is negative
2. Slip is positive and less than 1
3. Slip is zero
4. Slip is positive and greater than 1

Correct Option: 1

DDA JE Electrical ME 3 April 2023 Shift 1 Part 1

 

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