ECAT Physics — Electronics
Electronics is part of the Physics section of the UET ECAT (30 of the 100 MCQs). It breaks into 5 subtopics, and we hold 31 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (5)
How Electronics is tested
Across the 7 ECAT past papers on ParhaiKrlo, Electronics accounts for 16 questions. It appears in 6 of them, about 2.7 questions a paper. The heaviest was ECAT Past Paper 07, with 4 questions.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 4 |
| ECAT Past Paper 06 | 2 |
| ECAT Past Paper 05 | 3 |
| ECAT Past Paper 04 | 3 |
| ECAT Past Paper 03 | 2 |
| ECAT Past Paper 01 | 2 |
Electronics MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · Electronics
AC voltage is passed through a single-diode rectifier. The output of the rectifier is:
- A.Full-wave DC
- B.Half-wave DC
- C.Double-frequency DC
- D.None of these
Show answer
Answer: B. Half-wave DC — One diode passes only one half of each cycle.
- Q2 · ECAT Past Paper 06 · Electronics
Input X is connected to both inputs of a NAND gate whose output is Y. The relationship between Y and X is:
- A.Y = X
- B.Ȳ = X
- C.Y = X̄
- D.Both B and C
Show answer
Answer: D. Both B and C — A NAND with both inputs tied together is a NOT gate: Y = X̄, which can equally be written Ȳ = X.
- Q3 · ECAT Past Paper 05 · Electronics
Inputs A and B each pass through a NOT gate, and the two outputs are fed into a NAND gate whose output is Y. The system is equivalent to which gate?
- A.NOR
- B.NAND
- C.OR
- D.XOR
Show answer
Answer: C. OR — Y = NOT(Ā · B̄) = A + B by De Morgan's law: an OR gate.