Basic Electrical Engineering MCQ Part 2

Basic Electrical Engineering MCQ Part 2

Point Source Example

The figure below displays an electric circuit drawn using point source:

The voltmeter connected across 15 kohm resistor will read:

1. 3 V
2. 5 V
3. 10 V
4. 15 V

Correct answer: 4. 15 V

Explanation:

The circuit redrawn to normal circuit as follows:

Total input: Vin = 25 V

Using voltage divider rule:

V (15k) = (15 kohm)/(10 kohm + 15 kohm) * 25 V = 15 V

Resistance calculation for 5 ohms wire whose length is increased four times and area by two times

A certain length of wire has resistance 5 ohms. What is the resistance of wire that is made of the same material and is four times longer and has twice the cross-sectional area:

1. 2.5 ohms
2. 5 ohms
3. 7.5 ohms
4. 10 ohms

Correct answer: 2 ohms

Explanation: Suppose R₁ and R₂ are values of resistances and R₁ = 5 ohms.

From Formula R₁ = ρ*l₁/a₁ and R₂ = ρ*l₂/a₂

R₂/R₁ = (l₂/l₁) * (a₁/a₂)

R₂/R₁ = (4.l/l) * (a/2a) = (4.l/l) * (a/2a) = 4/2 = 2

R₂ = 2.R₁ = 2. 5 ohms = 10 ohms

For constant resistor by increasing the voltage the current will

For constant resistor, by increasing the voltage, the current will:

1. Increase
2. Decrease
3. Remain the same

Correct answer: 1. Increase

3 mA current flowing through 1 kohm resistance will produce a voltage drop of

3 mA current flowing through 1 kohm resistance will produce a voltage drop of:

1. 0.33 V
2. 1 V
3. 3 V
4. 3 mV

Correct answer: 3. 3 V

Norton theorem is ___________ Thevenin theorem

Norton’s theorem is ___________ Thevenin’s theorem:

1. Identical to
2. Converse of

Correct answer: 2. Converse of

Explanation:

Statement of Norton’s theorem: A linear bilateral network can be reduced to a simplified two-terminal circuit consisting of a single current source and a single shunt resistor

Statement of Thevenin Theorem: A linear bilateral network can be reduced to a simplified two-terminal circuit consisting of a single voltage source and a single series resistor