Electronics and Communication Engineering - Electronic Devices and Circuits

36.
Which display device resembles vacuum tube?
LED
LCD
VF
None of these
Answer: Option
Explanation:

It is similar to triode.


37.
The number of inputs and outputs of a full adder are
3 and 2 respectively
2 and 3 respectively
4 and 2 respectively
2 and 4 respectively
Answer: Option
Explanation:

Inputs are carry from lower bits and two other bits. Outputs are SUM and CARRY.


38.
A VF display operates on the principle of a vacuum diode.
True
False
Answer: Option
Explanation:

It operates on the principle of vacuum triode.


39.
In a 3 input NAND gate, the number of states in which output is 0 equals
8
1
6
5
Answer: Option
Explanation:

Only one input, i.e., A = 1, B = 1 and C = 1 gives low output.


40.
In a mod-12 counter the input clock frequency is 10 kHz. The output frequency is
0.833 kHz
1.0 kHz
0.91 kHz
0.77 kHz
Answer: Option
Explanation:

Mod-12 counter is divide by 12 counter. Output frequency = = 0.833 kHz.