Question

• A cross-over requires
Answer
A. Two sets of switches and two
crossings
B. Two sets of switches and four
crossings
C. Four sets of switches and four
crossings
D. None of these​

Answer 1

Answer:

subscribe my channel c2kmonstergamer

Answer 2

Answer:

B. Two sets of switches and four crossings

Explanation:

For a cross over to take place two sets of switches are required with four possible crossings

Lets take an example

there are two sets of switches A and B

  A set has a and a'

   B set has b and b'          

                      A set                                                       B set

              a                     a'                                     b                   b'    

When the crossing takes place the following combinations occur

1. a - b
2. a - b'
3. a' - b
4. a' - b'

Hence the answer is B. Two sets of switches and four crossings.