Electronics and Communication Engineering - Electronic Devices and Circuits

11.
A 4 bit down counter starts counting from 1111 irrespective of modulus.
True
False
Answer: Option
Explanation:

The starting count depends on modulus. 4 bit decade down counter starts counting from 1010.


12.
The number of counter states which an 8 bit stair step A/D converter has to pass through before conversion takes place is equal to
1
8
255
256
Answer: Option
Explanation:

28 = 256.


13.
74 HC series can sink upto 4 mA. The 74 LS series has IIL(max) - 0.4 mA. How many 74 LS inputs be driven by 74 HC output?
100
none
8
10
Answer: Option
Explanation:

.


14.
An 8 bit transistor register has output voltage of low-high-low-high-low-high-low-high. The decimal number stored is
105
95
85
75
Answer: Option
Explanation:

01010101 in binary and 64 + 16 + 4 + 1 = 85 in decimal.


15.
The number of cells in a 4 variable K map is
16
8
4
32
Answer: Option
Explanation:

24 = 16.