WorksheetsQuiz (EE-PC 318 Logic Circuits & Switching Theory)
Total questions: 50
Worksheet time: 25mins
A JK flip-flop changes its state when:
J = 1, K = 1
J = 0, K = 0
J = 1, K = 0
J = 0, K = 1
A D flip-flop is primarily used for:
Frequency division
Data storage
Addition operations
Subtraction operations
The output of a D flip-flop depends on:
Both previous and current inputs
Only current input
Clock pulses only
Both J and K inputs
In JK flip-flops, the condition J = 0 and K = 1 produces:
Toggle state
Set state
Reset state
No change
The primary difference between JK and D flip-flops is:
JK has no toggling feature
D flip-flop has one input, while JK has two
JK is faster than D flip-flop
JK flip-flop operates without a clock
The 7-segment display typically uses:
Liquid crystals
Light-emitting diodes (LEDs)
Plasma screens
Resistive touch
A BCD to 7-segment decoder is designed to convert:
Binary to hexadecimal
Binary-coded decimal to segment control signals
Binary to octal
Decimal to binary
In a common cathode 7-segment display, the cathodes of all LEDs are:
Individually controlled
Connected to Vcc
Connected to ground
Unused
When the input to a BCD to 7-segment decoder is 0000, the display shows:
1
0
Blank
8
The segment labeled "a" in a 7-segment display illuminates when:
Only input bit 1 is high
A specific combination of bits is high
All input bits are high
No input bits are high
A K-map is primarily used to:
Perform arithmetic calculations
Minimize Boolean expressions
Create flip-flop circuits
Generate truth tables
A K-map with 4 variables has how many cells?
8
16
32
4
In a 3-variable K-map, adjacent cells differ by:
One bit
Two bits
Three bits
Four bits
What is the primary rule for grouping 1's in a K-map?
Groups must contain an even number of cells
Groups can overlap
Groups must be rectangular and in powers of 2
Groups cannot be adjacent
A "don't care" condition in K-maps is represented as:
0
1
X
Z
IC 74LS247 is designed to work with which type of 7-segment display?
Common anode
Common cathode
Both common anode and cathode
Neither
The 74LS247 decoder outputs are:
Active high
Active low
Tri-state
Analog
How many input bits does the 74LS247 accept?
3
4
7
8
What will the output display of 74LS247 be if the input is 0101?
3
5
7
Blank
Which of the following ICs can serve as an alternative to the 74LS247?
74LS244
74LS157
74LS48
74LS00
The 74LS400 IC contains:
XOR gates
NAND gates
AND gates
NOR gates
How many NAND gates are inside the 74LS400?
2
3
4
6
The logic equation for a NAND gate is:
A) A + B = Y
B) (A · B)' = Y
C) A' · B' = Y
D) A + B' = Y
A 2-input NAND gate outputs logic high when:
Both inputs are high
Both inputs are low
One input is high, and one is low
At least one input is low
What is the propagation delay of a typical 74LS400 NAND gate?
10 ns
15 ns
25 ns
30 ns
The clock signal in a flip-flop is used to:
Reset the circuit
Synchronize data transfer
Hold the state indefinitely
Control power consumption
In a D flip-flop, the "D" stands for:
Data
Delay
Direct
Digital
A JK flip-flop is set to toggle mode when:
J = 0, K = 1
J = 1, K = 0
J = 1, K = 1
J = 0, K = 0
A master-slave JK flip-flop is designed to:
Double the frequency of the input
Avoid race conditions
Eliminate clock signals
Reduce power consumption
The main advantage of D flip-flops over SR flip-flops is:
A) Simpler design
B) Reduced clock dependency
C) Elimination of invalid states
D) Faster operation
A common anode 7-segment display requires:
Active-high inputs for segments to glow
Active-low inputs for segments to glow
Constant Vcc for all segments
Independent cathode connections
The 7-segment display segment connections are labeled as:
P, Q, R, S, T, U, V
a, b, c, d, e, f, g
X, Y, Z, W, P, Q, R
D0, D1, D2, D3
The decimal number 7 is represented in BCD as:
1110
0111
1010
1001
The digit 8 in a 7-segment display requires how many segments to glow?
5
6
7
4
The BCD to 7-segment decoder can handle input numbers in which range?
0-15
0-9
0-7
1-10
In a 2-variable K-map, a group of four cells represents:
A single variable
A constant value
A minimized term
A zero expression
In a K-map, two adjacent 1's are simplified into:
A 2-variable term
A single variable term
A 3-variable term
A constant
If a K-map has 16 cells, how many variables does it represent?
3
4
5
6
Which of the following is true about K-map minimization?
Larger groups result in more variables
Smaller groups reduce expression size
Larger groups reduce the number of terms
Groups cannot overlap
"Don't care" conditions in K-maps are used to:
Minimize the number of variables
Simplify expressions further
Increase expression complexity
Ignore certain inputs
The 74LS247 decoder IC is compatible with:
Hexadecimal inputs
BCD inputs
Octal inputs
Decimal inputs
The outputs of the 74LS247 are inverted because:
It drives a common cathode display
It operates with a high voltage
It drives a common anode display
It saves power
What is the main use of the 74LS247 IC?
Addition of binary numbers
Driving 7-segment displays
Memory management
Timing signals
The input combination 1010 on a 74LS247 will display:
8
A
5
Blank
Which pin on the 74LS247 IC is the ground pin?
Pin 10
Pin 12
Pin 14
Pin 16
NAND gates are considered universal because:
They cannot form any other gate
They can form all other gates
They are not affected by noise
They consume less power
The typical fan-out of a 74LS400 IC is:
5
10
15
20
A 3-input NAND gate outputs logic low only when:
All inputs are high
All inputs are low
At least one input is low
Two inputs are high
In the 74LS400 IC, unused inputs should be:
Left floating
Tied to Vcc
Tied to ground
Connected to the output
The power supply range for a 74LS400 IC is typically:
3.3V - 5V
5V - 12V
1.8V - 3.3V
10V - 15V
