Which of the following pair is/are correct? I. Astable multivibrator - Flip Flop II. Bistable multivibrator - Free running
Neither I nor II
Understanding Multivibrator Types in Electronics
Multivibrators are fundamental electronic circuits used to implement different types of switching and timing functions. They are categorized based on the number of stable states they possess. The three main types are Astable, Monostable, and Bistable multivibrators.
Analyzing Astable Multivibrators
An Astable multivibrator has no stable states. It continuously oscillates between two unstable states without requiring any external trigger signal. Because of this continuous oscillation, it is often referred to as a free-running oscillator. It produces a repetitive waveform (like square or rectangular waves) at its output.
Analyzing Bistable Multivibrators
A Bistable multivibrator has two stable states. It can remain in either state indefinitely until an external trigger pulse is applied. A trigger pulse is required to switch the circuit from one stable state to the other. Once triggered, it stays in the new state until another trigger pulse prompts it to switch back. This behavior makes the bistable multivibrator ideal for use as memory elements or flip-flops.
Relationship with Flip-Flops and Free Running
- A Flip-Flop is essentially a type of bistable multivibrator. It has two stable states and is used to store binary information (0 or 1). It requires a clock signal or trigger pulses to change its state.
- Free running describes the characteristic of a circuit that oscillates continuously without needing an external trigger. This is the defining feature of an Astable multivibrator.
Evaluating the Given Statements
Let's examine the two statements provided:
- Astable multivibrator - Flip Flop: As discussed, an Astable multivibrator is a free-running oscillator with no stable states. A Flip-Flop is a Bistable multivibrator with two stable states. Therefore, this pair is incorrect.
- Bistable multivibrator - Free running: A Bistable multivibrator has two stable states and requires external triggers to change state. Free running describes an Astable multivibrator which oscillates continuously without triggers. Therefore, this pair is incorrect.
Based on the analysis, neither statement correctly pairs the multivibrator type with the associated concept or circuit.
Conclusion on the Correct Pair
Since both Statement I and Statement II are incorrect, the correct option is that neither pair is correct.
| Type | Stable States | Trigger Required? | Common Name/Characteristic |
|---|---|---|---|
| Astable | None | No (Oscillates Freely) | Free-running oscillator |
| Monostable | One | Yes (To enter unstable state) | One-shot multivibrator |
| Bistable | Two | Yes (To switch between states) | Flip-flop, Latch |
Revision Table: Multivibrators and States
Here is a quick summary to help distinguish between the types of multivibrators:
| Feature | Astable | Monostable | Bistable |
|---|---|---|---|
| Number of Stable States | 0 | 1 | 2 |
| Trigger Needed? | No | Yes (for the single pulse) | Yes (to change state) |
| Output Waveform | Continuous oscillation | Single pulse of fixed width | Stays constant until triggered |
| Also Known As | Free-running oscillator | One-shot | Flip-flop, Latch |
Additional Information on Multivibrator Applications
Multivibrators have various applications in electronics:
- Astable Multivibrators: Used as clock pulse generators, in timing circuits, and for generating waveforms in synthesizers.
- Monostable Multivibrators: Used for pulse stretching, time delays, and missing pulse detection.
- Bistable Multivibrators (Flip-Flops): Form the basis of memory elements in digital circuits, used in counters, registers, and sequential logic circuits. They are fundamental building blocks for storing data in computers and other digital systems.
Understanding the number of stable states is key to identifying the type of multivibrator and its potential applications.
Important Questions from Flip-Flop
In D flip-flop, if D = 1, then the output of the D flip-flop is ______, but if D = 0, then the output of D flip-flop goes to ______ state.
Which of the following statements about the T-type flip-flop is correct?
I. If T = 1, Changes the state of the lining clock pulse.
II. If T = 0, the state does not change.
For a JK Flip‐flop
A. When J = 0, K = 1, Q n+1 = 0
B. When J = 1, K = 1, Q n+1 = 1
C. When J = 1, K = 1, Q n+1 =\(\rm \overline{Q_n}\)
D. When J = 1, K = 0, Q n+1 = 1
E. When J = 1, K = 0, Q n+1 = 0
Choose the correct answer from the options given below:
Toggle condition is present in which of the following?
In a JK flip flop output Qn = 1 and it does not change when a clock pulse is applied. What is the possible combination of inputs (Jn, Kn) in this condition ('X' denotes don't care)
