In this section of Electronic Devices and Circuits.It contain Current and Voltage Sources MCQs (Multiple Choice Questions Answers).All the MCQs (Multiple Choice Question Answers) requires in depth reading of Electronic Devices and Circuits Subject as the hardness level of MCQs have been kept to advance level.These Sets of Questions are very helpful in Preparing for various Competitive Exams and University level Exams.

**This Section covers below lists of topics :**

- Sources of Electrical Power MCQs.
- Internal Resistance and impedence MCQs.
- Ideal Voltage Source ,Real Voltage source MCQs.
- Current Source,Ideal Current Source ,Real Current Source MCQs.
- Maximum Power Transfer Theorem MCQs.
- Thevenin Theorem MCQs.

**Practice it now to sharpen your concept.**

#### 1. An ideal voltage source is that which has an internal resistance

- Zero
- low
- High
- Infinite

#### 2. An ideal current source is that which has an internal resistance

- Zero
- High
- Low
- infinite

#### 3. A Practical constant voltage source should have internal resistance

- Zero
- Low
- High
- infinite

#### 4. A Practical constant Current source should have internal resistance

- Zero
- Low
- High
- Infinite

#### 5. Maximum Power will be transferred from a source having internal resistance 15 Ohm when load resistance will be

- 150 OHM
- 5 OHM
- 15 OHM
- None of these

#### 6. When the load resistance is equal to the internal resistance of the source ,the efficiency will be

- 100%
- 80%
- 20%
- None of these

#### 7. An ideal voltage source of 12 V provides a current of 150 mA to a load. if the load resistance is doubled the new load current becomes

- 150mA
- 75mA
- 300mA
- none of these

#### 8. An ideal current source supplies the current of 200mA to a load of 1 kOHM .when the load is changed to 100 OHM. the load current will be

- 200mA
- 2000mA
- 20mA
- None of these

#### 9. To determine current in 3 kohm resistor in the circuit shown in figure below with Rl= 6kohm According to the thevenin theorem the network is reduced to a source having the value of Eth and Rth as

- 6v,3kohm
- 12 v ,9kohm
- 9v,12kohm
- 12v,6kohm

**Thevenin’s Theorem** states that “*Any linear circuit containing several voltages and resistances can be replaced by just one single voltage in series with a single resistance connected across the load*“. In other words, it is possible to simplify any electrical circuit, no matter how complex, to an equivalent two-terminal circuit with just a single constant voltage source in series with a resistance (or impedance) connected to a load

#### 10. solving of an electrical circuit will give same result whether the source is treated as a voltage source or as a current source

- True
- False
- None

#### 11. An ideal voltage source has

- Zero internal resistance
- Infinite internal resistance
- A load-dependent voltage
- A load-dependent current

#### 12. A real voltage source has

- Zero internal resistance
- Infinite internal resistance
- A small internal resistance
- A large internal resistance

#### 13. If a load resistance is 1 kΩ, a stiff voltage source has a resistance of

- At least 10 ohm
- Less than 10 ohm
- More than 100 kΩ
- Less than 100 kΩ

#### 14. An ideal current source has

- Zero internal resistance
- Infinite internal resistance
- A load-dependent voltage
- A load-dependent current

#### 15. A real current source has

- Zero internal resistance
- Infinite internal resistance
- A small internal resistance
- A large internal resistance

#### 16. If a load resistance is 1 kΩ, a stiff current source has a resistance of

- At least 10 ohm
- Less than 10 ohm
- More than 100 kΩ
- Less than 100 kΩ

#### 17. The Thevenin voltage is the same as the

- Shorted-load voltage
- Open-load voltage
- Ideal source voltage
- Norton voltage

#### 18. The Thevenin resistance is equal in value to the

- Load resistance
- Half the load resistance
- Internal resistance of a Norton circuit
- Open-load resistance

#### 19. To get the Thevenin voltage, you have to

- Short the load resistor
- Open the load resistor
- Short the voltage source
- Open the voltage source

#### 20. To get the Norton current, you have to

- Short the load resistor
- Open the load resistor
- Short the voltage source
- Open the current source

#### 21. The Norton current is sometimes called the

- Shorted-load current
- Open-load current
- Thevenin current
- Thevenin voltage

#### 22. A solder bridge

- may produce a short
- may cause an open
- is useful in some circuits
- always has high resistance

#### 23. A cold-solder joint

- shows good soldering technique
- usually produces an open
- is sometimes useful
- always has low resistance

#### 24. An open resistor has

- Infinite current through it
- Zero voltage across it
- Infinite voltage across it
- Zero current through it

#### 25. A shorted resistor has

- Infinite current through it
- Zero voltage across it
- Infinite voltage across it
- Zero current through it

#### 26. An ideal voltage source and an internal resistance is an example of the

- Ideal approximation
- Second approximation
- Higher approximation
- Exact model

#### 27. Treating a connecting wire as a conductor with zero resistance is an example of the

- Ideal approximation
- Second approximation
- Higher approximation
- Exact model

#### 28. The voltage out of an ideal voltage source

- Is zero
- Is constant
- Depends on the value of load resistance
- Depends on the internal resistance

#### 29. The current out of an ideal current source

- Is zero
- Is constant
- Depends on the value of load resistance
- Depends on the internal resistance

#### 30. Thevenin’s theorem replaces a complicated circuit facing a load by an

- Ideal voltage source and parallel resistor
- Ideal current source and parallel resistor
- Ideal voltage source and series resistor
- Ideal current source and series resistor

#### 31. Norton’s theorem replaces a complicated circuit facing a load by an

- Ideal voltage source and parallel resistor
- Ideal current source and parallel resistor
- Ideal voltage source and series resistor
- Ideal current source and series resistor

#### 32. One way to short a device is

- With a cold-solder joint
- With a solder bridge
- By disconnecting it
- By opening it