ISCET Cheat Sheet 2026

The 30 highest-yield ISCET facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which of the following Boolean expressions correctly represents one of De Morgan's theorems? → NOT (A AND B) = (NOT A) OR (NOT B)
2. When using a digital multimeter to measure resistance, the display shows "OL". What does this indicate? → The measured resistance is too high for the selected range, or the circuit is open.
3. What is the key difference between a latch and a flip-flop in digital sequential circuits? → Latches are level-triggered, while flip-flops are edge-triggered.
4. Which color is typically used for ground wires in electronics? → Green or green/yellow
5. Which component provides clock signals to synchronize operations in a microprocessor? → Clock Generator
6. In a P-N junction diode, what is the primary reason for the formation of the depletion region? → Recombination of majority carriers near the junction
7. Why are safety signs used in workshops? → To warn about risks and promote safe practices
8. How is total resistance calculated in a series circuit? → Add all resistances
9. The ripple factor (r) of a power supply filter is best described as: → The ratio of RMS ripple voltage to average DC output voltage
10. What is the binary equivalent of the decimal number 13? → 1101
11. What is the main function of an inductor in a circuit? → To store energy in a magnetic field
12. What type of document includes troubleshooting steps for repair? → Service manual
13. What should be done before using an oscilloscope? → Calibrate the probes and channels
14. Which register holds the address of the next instruction to be executed? → Program Counter
15. In a simple DC series circuit containing a 12V battery and three resistors (R1=10Ω, R2=20Ω, R3=30Ω), what is the total power dissipated by the circuit? → 2.4 W
16. Transformer voltage regulation (VR%) is calculated based on the change in secondary voltage between: → No-load and full-load conditions at rated input voltage
17. In a DC series circuit containing three resistors (R1=10Ω, R2=20Ω, R3=30Ω), what is the total resistance (Rt)? → 60 Ω
18. What does a caution symbol on technical documentation indicate? → Potential hazard requiring attention
19. According to Kirchhoff's Voltage Law (KVL), which of the following statements is true for any closed loop in a DC circuit? → The algebraic sum of all voltage drops and rises is zero.
20. In a three-terminal linear regulator circuit, what internal block compares the output sample voltage to the reference and drives the pass element? → The error amplifier
21. In a full-wave bridge rectifier, how many diodes conduct simultaneously during each half-cycle of the AC input? → Two
22. What is the unit of electrical resistance? → Ohm
23. A technician is analyzing an AC circuit and notes that the current waveform leads the voltage waveform. Which of the following best describes the load? → Primarily capacitive
24. In a switching power supply, the inductor's primary function during the switch off-time in a buck converter is to: → Act as an energy storage element that continues supplying current to the load
25. What is the primary advantage of a switching regulator over a linear regulator? → Higher power conversion efficiency
26. A half-wave rectifier is connected to a 120V RMS transformer secondary. What is the approximate average DC output voltage (ignoring diode drop)? → 54V
27. Why is it important to zero a multimeter before resistance measurement? → To ensure accurate resistance readings
28. The output voltage of an LM317 adjustable positive voltage regulator is set by: → An external resistor divider network connected to the ADJ pin
29. What is the primary purpose of a filter capacitor placed after a rectifier in a DC power supply? → To smooth the pulsating DC output by reducing ripple
30. When comparing a Bipolar Junction Transistor (BJT) to a Field-Effect Transistor (FET), which of the following is a key characteristic of the FET? → High input impedance