Electronics and Communication Engineering - Electronic Devices and Circuits

11.
A + A . B =
B
A . B
A
A or B
Answer: Option
Explanation:

A.B= 1 or 0, A + A.B = 0 if A is zero and A + A.B = 1 if A = 1. Hence A + A.B = A.


12.
The device 'one shot' has
two stable states
one stable state
either 1 or 2 stable states
no stable state
Answer: Option
Explanation:

One shot means one stable state.


13.
For the logic circuit of the given figure the simplified Boolean expression is
A + BC
A + BC
A + B C
A + BC
Answer: Option
Explanation:

= A + BC.


14.
If number of information bits is 4, the parity bits in Hamming code are located at bit positions __________ from the LSB.
1, 2, 5
1, 2, 4
1, 2, 3
1, 2
Answer: Option
Explanation:

The number of parity bits is 3. These bits are located at 20, 21, 22, i.e., 1, 2, 4th bits starting from LSB.


15.
A certain JK FF has tpd = 12 n sec the largest MOD counter that can be constructed from these FF and still operate up to 10 MHz is
any
8
256
10
Answer: Option
Explanation:

Clock period(t) = = 10-7 sec

Number of FF =

mod counter 28 = 256.