Rephrase this sentence: "MOSFET sizes are already chosen and their parameters are extensively tabulated in table1"

The MOSFET sizes have already been selected, and their parameters are thoroughly listed in Table 1.

Rephrase this also: "So the trick in designing this is to exploit two properties of this circuit."

Sure! Here's a rephrased version:

"The key to designing this lies in taking advantage of two characteristics of the circuit."

Rephrase: "We already know the desired current which is 10 A."

Certainly! Here's a rephrased version:

"We're already aware of the target current, which is 10 A."

Rephrase: "Point no 2 might seem like stating the obvious, but this will be proven wrong when we recall an important circuit theory concept."

Of course! Here's a rephrased version:

"Point number 2 may appear to be stating the obvious, but this will be shown to be incorrect once we remember an essential circuit theory concept."

Rephrase: "When we know the current through and voltage across an element in a network, we can replace that element with an ideal current or voltage source whose value is same as that of the element."

Certainly! Here's a rephrased version:

"Once we know the current through and the voltage across an element in a network, we can substitute that element with an ideal current or voltage source having the same value as the original element."