SSC JE electrical question paper explained 2016-2017

22 Comments / SSC previous year solved electrical papers / April 12, 2022

Ques 91. The leakage resistance of a 50 Km long cable is 1 MΩ. For a 100 Km long cable it will be

  1. 1 MΩ
  2. 2 MΩ
  3. 0.5 MΩ
  4. None of these

Answer.3. 0.5 MΩ

Explanation:

Leakage resistance of the cable α 1/Length

For 100 km long cable leakage resistance of cable

=50/100 =0.5MΩ

 

Ques 92. A series drawing an armature current of Is is operating under saturated magnetic conditions, the torque developed in the motor is proportional to

  1. 1/Ia
  2. 1/I2a
  3. I2a
  4. Ia

Answer.4. Ia

Explanation:

We know Torque Tα ΦIa As the motor is operating under saturation condition so torque will be independent of flux i.e. T α Ia.

 

Ques 93. The insulation resistance of a cable of length 10 Km is 1 MΩ. Its resistance for 50 Km length will be

  1. 1 MΩ
  2. 0.5 MΩ
  3. 0.2 MΩ
  4. None of these

Answer.2. 0.2 MΩ

Explanation:

Insulation resistance of the cable

R α 1/Length

R2/R1 = L1/L2

Hence, insulation resistance for 50 km length

R2 = (1 × 10)/50

= 0.2 MΩ

 

Ques 94. When a line-to-ground fault occurs, the current in a faulted phase is 100 A. The zero sequence current in the case will be

  1. Zero
  2. 33.3 A
  3. 66.6 A
  4. 100 A

Answer.2. 33.3 A

Explanation:

For LIne to ground fault, we know that

IN = If = 3Io

Where IN = Neutral current

If  = Fault current

Io = zero sequence current

Hence zero sequence current is

100/3 = 33.3 A

 

Ques 95. A 3 phase, 400-V, 50 Hz 4 pole induction motor is fed from a 3-phase supply and runs of 1425 rpm. The frequency of the rotor emf is

  1. 2.5 Hz
  2. 50 Hz
  3. 48 Hz
  4. Zero

Answer.1. 2.5 Hz

Explanation:

Synchronous speed

Ns = 120f/P

= 120 × 50/ 4

= 1500 rpm

Rotor speed = 1425 rpm

Slip = (Ns – Nr)/Ns

= (1500 – 1425)/1500

= 0.05

∴ Frequency of rotor emf

= 0.05 × 50

= 2.5 Hz

 

Ques 96. The field coils of a dynamo have an inductance of 8H and have a resistance of 60 ohms and are connected to 120 V dc source. The steady-state current in the field coiled is

  1. 15 A
  2. 2 A
  3. 0 A
  4. None of these

Answer.2. 2A

Explanation:

Steady-state field current = 120/60 = 2A

 

Ques 97. The surge impedance of a 50 miles long underground cable is 50 ohms. For a 25 miles length, it will be

  1. 25 Ω
  2. 50 Ω
  3. 100 Ω
  4. None of these

Answer.2. 50 ohms

Explanation:

Surge impedance is independent of the length of the line hence the surge impedance will remain 50 ohms

 

Ques 98. In a BJT with α = 0.98, β is equal to

  1. 49
  2. 98
  3. 0.49
  4. 980

 Answer.1. 49 

Explanation:

In CB mode current gain is

Ic/IE = α

In CC mode current gain is

β =IC/IB

and β = α (1 – α)

= 0.98/(1-0.98) = 49

 

Ques 99. Two coils in differential connection have self-inductance of 2 mH and 4 mH and a mutual inductance 0f 0.15 mH. The equivalent inductance of the combination is

  1. 5.7 mH
  2. 5.85 mH
  3. 6 mH
  4. 6.15 mH

Answer.1. 5.7 mH

Explanation:

Total inductance for differential connection is given as

Leq = L1 + L2 + 2M……………..1

= 2 + 4 – 2 x 0.15

= 5.7 mH

 

Ques 100. Find the value of I?

figure 4

  1. 10 A
  2. 13 A
  3. 17/2 A
  4. None of these

Answer.4. None of these

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22 thoughts on “SSC JE electrical question paper explained 2016-2017”

  2. Arup Ghoshal

    respected sir,here is only 100 questions. Can you please send me the full set of 2017 solved papers with explanation. Please sir help me. This website is very helpful to me.

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