Electronics and Communication Engineering - Electronic Devices and Circuits

46.
A 3 bit up-down counter can count from
000 to 111
111 to 000
000 to 111 and also from 111 to 000
none of the above
Answer: Option
Explanation:

Since it is an up-down counter it can count upwards or downwards.


47.
The density of dynamic RAM is
the same as static RAM
less than that of static RAM
more than that of static RAM
either equal or less than that of static RAM
Answer: Option
Explanation:

Dynamic RAM has higher packing density and requires lesser space.


48.
The gates G1 and G2 in the figure have propagation delays of 10 n sec. and 20 n sec. respectively. If the input Vi makes an output change from logic 0 to 1 at time t = t0 then the output wavefrom V0 is
Answer: Option
Explanation:

Truth table are as follows.


49.
A 3 input NAND gate is to be used as inverter. Which of the following will give better results?
The two unused inputs are left open
The two unused inputs are connected to 0
The two unused inputs are connected to 1
None of the above
Answer: Option
Explanation:

Unused inputs should be given high input.


50.
The maximum counting range of a four stage counter using IC 74193 is
0 to 1023
0 to 4093
0 to 65535
0 to 131071
Answer: Option
Explanation:

IC 74193 is a divide by 16 counter.

Since 4 stages are used, counting range = 164 = 65536.