Quiz: Electrical Engineering
Exam: UPSSSC JE
Topic: Miscellaneous
Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute
Q1. Resistance of an ammeter having range 0–5A is 1.8 Ω. It is shunted by a resistor of 0.2 Ω. What is the effective current when the pointer reads 2 A?
(a) 10 A
(b) 30 A
(c) 15 A
(d) 20 A
L1Difficulty 2
QTags Measurement and measuring instrument
QCreator Balwant Kumar
Q2. The overall efficiency of a steam power station is ………. its thermal efficiency.
(a) less than
(b) more than
(c) equal to
(d) none of the above
L1Difficulty 1
QTags Power generation, transmission and distribution
QCreator Balwant Kumar
Q3. In a power station,
(a) Reserve capacity = Plant capacity + Max. demand
(b) Reserve capacity = Plant capacity – Average demand
(c) Reserve capacity = Plant capacity – Max. demand
(d) Reserve capacity = Plant capacity + Average demand
L1Difficulty 1
QTags Power generation, transmission and distribution
QCreator Balwant Kumar
Q4. In a 3-phase system, the line losses are
(a) directly proportional to cos ϕ
(b) inversely proportional to cos ϕ
(c) inversely proportional to cos² ϕ
(d) none of the above
L1Difficulty 1
QTags Power generation, transmission and distribution
QCreator Balwant Kumar
Q5. Superposition theorem is essentially based on the concept of
(a) Reciprocity
(b) Linearity
(c) Duality
(d) Non-linearity
L1Difficulty 1
QTags Network theorems
QCreator Balwant Kumar
Q6. One coulomb of electrical charge is contributed by how many electrons?
(a) 0.625×10^19
(b) 1.6×10^19
(c) 10^19
(d) None of these
L1Difficulty 1
QTags Basic electrical engineering
QCreator Balwant Kumar
Q7. A current is said to be alternating when it changes in:
(a) Magnitude
(b) Direction
(c) Both magnitude and direction
(d) None of these
L1Difficulty 1
QTags AC fundamentals
QCreator Balwant Kumar
Q8. Voltage applied across a ceramic dielectric produces an electrostatic field 100 times greater than in air. The dielectric constant of the ceramic equals_________.
(a) 100/3
(b) 50
(c) 100
(d) 1/100
L1Difficulty 1
QTags Switchgear and protection
QCreator Balwant Kumar
Q9. Internal heating of capacitor is usually attributed to_________.
(a) dielectric charge
(b) plate vibration
(c) electron movement
(d) leakage resistance
L1Difficulty 2
QTags Basic electrical engineering
QCreator Balwant Kumar
Q10.In a parallel circuit operating with a source of 30 V AC, designed to carry a total current of 6 A, what happens to the protection device (fuse) when the resistance suddenly changes to 2Ω?
(a) It closes
(b) There is no change
(c) It shorts to ground
(d) It opens
L1Difficulty 1
QTags AC fundamentals
QCreator Balwant Kumar
Solution
S1.(D)
Sol. Multiplying power of shunt, n=(G+S)/S=G/S+1=1.8/0.2+1=10
Therefore, the range of ammeter increases 10 times. When the ammeter indicates 2 A, the circuit current = 2 ×10 = 20 A.
S2.(A)
Sol. The overall efficiency of a steam power station is less than its thermal efficiency. This is expected since some losses (about 1%) occur in the alternator.
S3.(C)
S4.(C)
Sol. Line current,
Since line losses are proportional to the square of , it follows that line losses are proportional to 1/cos² ϕ
S5. (b) Superposition theorem is used in the linear circuits having more than one independent voltage or current sources.
S6. Ans.(a)
Sol. One coulomb has 0.625 × 1019 electron
S7. Ans.(c)
Sol.
A current is said to be alternating when it changes in both magnitude and direction
S8. (c)
Electric field due to ceramic dielectric = k ; V = Applied voltage
∴ E ∝ k If = constant K = Dielectric constant
For air K = 1
∴ ⇒
= Dielectric constant for ceramic
S9. (d)
Leakage resistance
S10. (d)
Initial resistance of circuit = = 5 Ω
Rated current = 6A
Now,
Here, I > ⇒ Fuse opens
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