Basic Electrical Engineering MCQs Part 28
Contents
- 1 In gases the flow of current is due to:
- 2 The temperature coefficient of resistance of certain wire is 0.00150 per °C. At 300 K, its resistance is 1 Ω. The resistance of wire will be 2 Ω at what temp value
- 3 The total charge entering terminal of an element is given by equation
- 4 No current flows between two charged bodies when they have same
- 5 The rating of the fuse wire is always expressed in
In gases the flow of current is due to:
In gases the flow of current is due to:
- Positive ions only
- Electrons only
- Electrons and positive ions
- Electrons, positive ions and negative ions
Correct answer: 4. Electrons, positive ions and negative ions
The temperature coefficient of resistance of certain wire is 0.00150 per °C. At 300 K, its resistance is 1 Ω. The resistance of wire will be 2 Ω at what temp value
The temperature coefficient of resistance of certain wire is 0.00150 per °C. At 300 K, its resistance is 1 Ω. The resistance of wire will be 2 Ω at what temp value:
- 585.53 K
- 966.66 K
- 1052.33 K
- 2200 K
Correct answer: 2. 966.66 K
Explanation:
The resistance of wire at 300 K or 27° C is 1 Ω. (Since Celsius = Kelvin – 273.15)
Let’s assume R1 = 1 Ω
Let’s assume at t° C the resistance of wire is 2 Ω
From formula:
R2 = R1 [ 1 + α (t – 27) ]
Where α = Temperature coefficient of resistance
OR
2 = 1 [ 1 + 0.0015 (t – 27)]
Solving above:
t = 693.66° C
Temp in Kelvin
t = 693.66 + 273 = 966.66 K
The total charge entering terminal of an element is given by equation
The total charge entering terminal of an element is given by equation:
q = (9t2 – 15t)mC
The current at t = 3s is:
- 3 mA
- 6 mA
- 12 mA
- 18 mA
Correct answer: 3. 12 mA
Explanation:
i = dq/dt = d/dt (q) = d/dt (9t2 – 15t) mA = (9t – 15) mA
At t = 3s
i = 9(3) – 15 = 12 mA
No current flows between two charged bodies when they have same
No current flows between two charged bodies when they have same
- Charge
- Capacity
- Potential
- None of the above
Correct answer: 3. Potential
The rating of the fuse wire is always expressed in
The rating of the fuse wire is always expressed in:
- Ampere
- Ampere-hours
- Volts
- kWH
Correct answer: 1. Ampere
Read more: Electrical Engineering MCQs here
Also study:
- Basic Electrical Laws and Theorems
- Basic Voltage and Current MCQs
- High Voltage Engineering MCQs
- Induction Motor MCQs
- Power Electronics
- Power Distribution MCQs
- Power Generation MCQs
- Power System Protection MCQs
- Synchronous Generator MCQs
- Synchronous motor MCQs
- Transformer MCQs