Q1. A flip-flop is used for:

A) Amplification
B) Storage of 1 bit
C) Signal conversion
D) Voltage regulation

Answer: B) Storage of 1 bit

Explanation:
A flip-flop is a basic memory element used to store one binary bit (0 or 1).

Q2. The simplest memory element is:

A) Counter
B) Register
C) Latch
D) Encoder

Answer: C) Latch

Explanation:
Latch is the simplest storage device and forms the basis of flip-flops.

Q3. SR flip-flop stands for:

A) Set Reset
B) Shift Register
C) Serial Register
D) Signal Reset

Answer: A) Set Reset

Explanation:
SR flip-flop has two inputs: Set (S) and Reset (R).

Q4. In SR flip-flop, S = 1 and R = 0 means:

A) Reset
B) Set
C) No change
D) Invalid

Answer: B) Set

Explanation:
When S = 1 and R = 0, output Q becomes 1.

Q5. In SR flip-flop, S = 0 and R = 1 means:

A) Set
B) Reset
C) Toggle
D) Invalid

Answer: B) Reset

Explanation:
When R = 1, output Q becomes 0.

Q6. In SR flip-flop, S = 1 and R = 1 is:

A) Valid
B) Toggle
C) Invalid
D) Set

Answer: C) Invalid

Explanation:
This condition is not allowed because output becomes uncertain.

Q7. JK flip-flop removes the problem of:

A) Speed
B) Invalid state of SR flip-flop
C) Power
D) Clock pulse

Answer: B) Invalid state of SR flip-flop

Explanation:
JK flip-flop solves the invalid condition of SR flip-flop.

Q8. In JK flip-flop, J = 1 and K = 1 causes:

A) Set
B) Reset
C) Toggle
D) Hold

Answer: C) Toggle

Explanation:
Output changes from 0 to 1 or 1 to 0.

Q9. T flip-flop is mainly used for:

A) Addition
B) Toggling
C) Encoding
D) Decoding

Answer: B) Toggling

Explanation:
T flip-flop changes state on every clock pulse when T = 1.

Q10. D flip-flop stands for:

A) Data
B) Digital
C) Delay
D) Both A and C

Answer: D) Both A and C

Explanation:
D flip-flop is called Data or Delay flip-flop.

Q11. D flip-flop avoids:

A) Race condition
B) Invalid state
C) Memory loss
D) Clock delay

Answer: B) Invalid state

Explanation:
D flip-flop has only one input, so invalid condition does not occur.

Q12. Shift register is used for:

A) Data storage and shifting
B) Voltage conversion
C) Frequency generation
D) Display control

Answer: A) Data storage and shifting

Explanation:
Shift registers store and shift binary data left or right.

Q13. SISO means:

A) Serial In Serial Out
B) Serial In Signal Out
C) Single Input Single Output
D) Signal In Signal Out

Answer: A) Serial In Serial Out

Explanation:
Data enters serially and leaves serially.

Q14. SIPO means:

A) Serial In Parallel Out
B) Single In Parallel Out
C) Signal In Pulse Out
D) Serial In Pulse Out

Answer: A) Serial In Parallel Out

Explanation:
Input is serial, output is available in parallel form.

Q15. PISO means:

A) Parallel In Serial Out
B) Pulse In Signal Out
C) Parallel In Shift Out
D) Parallel Input Signal Output

Answer: A) Parallel In Serial Out

Explanation:
Parallel data is loaded and output comes serially.

Q16. PIPO means:

A) Parallel In Parallel Out
B) Pulse In Pulse Out
C) Program In Program Out
D) Parallel In Pulse Out

Answer: A) Parallel In Parallel Out

Explanation:
Data enters and exits in parallel form.

Q17. Ring counter is made using:

A) Decoder
B) Shift Register
C) Comparator
D) Encoder

Answer: B) Shift Register

Explanation:
Ring counter is a circular shift register.

Q18. Counter is used for:

A) Counting pulses
B) Amplifying signals
C) Voltage control
D) Logic simplification

Answer: A) Counting pulses

Explanation:
Counters count clock pulses and events.

Q19. Ripple counter is also called:

A) Synchronous counter
B) Asynchronous counter
C) Ring counter
D) Down counter

Answer: B) Asynchronous counter

Explanation:
In ripple counters, output of one flip-flop clocks the next.

Q20. In synchronous counter:

A) All flip-flops share same clock
B) Different clocks are used
C) No clock is used
D) Random pulses are used

Answer: A) All flip-flops share same clock

Explanation:
This makes synchronous counters faster than ripple counters.

Q21. Asynchronous counters are:

A) Faster
B) Slower
C) Equal speed
D) No speed difference

Answer: B) Slower

Explanation:
Because of propagation delay, asynchronous counters are slower.

Q22. Mod-10 counter is also called:

A) Binary counter
B) Decade counter
C) Ring counter
D) Up counter

Answer: B) Decade counter

Explanation:
It counts from 0 to 9 (10 states).

Q23. Sequence generator is used to:

A) Generate binary sequence
B) Add numbers
C) Compare values
D) Decode outputs

Answer: A) Generate binary sequence

Explanation:
It produces a fixed sequence of binary outputs.

Q24. Application of flip-flop includes:

A) Memory
B) Counter
C) Register
D) All of these

Answer: D) All of these

Explanation:
Flip-flops are widely used in all these circuits.

Q25. Register is a group of:

A) Logic gates
B) Flip-flops
C) Counters
D) Encoders

Answer: B) Flip-flops

Explanation:
Registers are made by combining multiple flip-flops.

Q26. A 4-bit register stores:

A) 2 bits
B) 4 bits
C) 8 bits
D) 16 bits

Answer: B) 4 bits

Explanation:
Each flip-flop stores 1 bit, so 4 FF = 4-bit register.

Q27. Up counter counts:

A) Decreasing order
B) Increasing order
C) Random order
D) Parallel order

Answer: B) Increasing order

Explanation:
Example: 000 → 001 → 010 → 011...

Q28. Down counter counts:

A) Increasing order
B) Decreasing order
C) Circular order
D) Mixed order

Answer: B) Decreasing order

Explanation:
Example: 111 → 110 → 101 → 100...

Q29. Flip-flops are generally triggered by:

A) Clock pulse
B) Voltage source
C) Current source
D) Resistance

Answer: A) Clock pulse

Explanation:
Clock pulse controls the timing of flip-flop operation.

Q30. Which flip-flop is best for frequency division?

A) D flip-flop
B) T flip-flop
C) SR flip-flop
D) JK flip-flop

Answer: B) T flip-flop

Explanation:
T flip-flop toggles every clock pulse and is ideal for frequency division.