ANS:C - 6

72 = 9 x8, where 9 and 8 are co-prime. The minimum value of x for which 73x for which 73x is divisible by 8 is, x = 6. Sum of digits in 425736 = (4 + 2 + 5 + 7 + 3 + 6) = 27, which is divisible by 9. Required value of * is 6.

ANS:B - The energy of steam was discovered by James Watt.

No answer description is available. 

ANS:A - Yes

No answer description is available. Let's discuss.

ANS:C - parallel-to-serial data conversion

Parallel means many & serial means one.

Mux has many inputs and one output.

So, it is used in the application of parallel to serial conversion.

ANS:A - Parity checking is best suited for detecting single-bit errors in transmitted codes.

Parity is a bit checker so if Even no.of error occur it won't ditinguish.
EX: Data to b transmitted= 1010101
Even parity of 1010101 is '0' (if odd parity '1')
Let the data transmitted as
1. 1000101 - single bit error; parity is '1'
2. 1001101 - two bits error; parity is '0'

Therefore in 1 (ie single bit error) parity is missmatch

[Parity is calculated by just adding no.of ones; if we follow even parity then over count shd be 0, if not we shd set ie make parity as 1]

ANS:B - uses one display to present two or more pieces of information

More pieces of information means more than 1 i/p & 1display means 1 O/p. MUX is multi i/p single O/p circuit.

ANS:B - priority encoding

When two or more line are active then only we can determine to whom we have to give first priority.

ANS:A - hexadecimal

It is given as 16 outputs and 4 input i.e. 4*16 decoder. As binary is 0 and 1. So obviously it's hexadecimal decoder.

ANS:C -

ANS:C - encoder

Encoder is a digital circuit which performs reverse operation of a decoder and the output line generate the binary code corresponding to the input value.