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1. What is the unit of electrical resistance? A) Volt B) Ampere C) Ohm D) Watt **ANSWER : C
- Ohm's Law states that voltage equals:** A) Current divided by resistance B) Current multiplied by resistance C) Resistance divided by current D) Power multiplied by current **ANSWER : B
- Which component stores electrical charge?** A) Resistor B) Inductor C) Capacitor D) Diode **ANSWER : C
- The unit of electrical current is the:** A) Volt B) Ampere C) Farad D) Henry **ANSWER : B
- What does AC stand for in electronics?** A) Alternating Current
B) Active Circuit C) Ampere Constant D) Applied Current ANSWER : A
6. A resistor color code of red-red-red represents: A) 220 Ω B) 2200 Ω C) 22 Ω D) 22000 Ω **ANSWER : B
- Which device allows current to flow in only one direction?** A) Transistor B) Capacitor C) Diode D) Transformer **ANSWER : C
- The formula for electrical power is:** A) P = V + I B) P = V / I C) P = V × I D) P = V - I **ANSWER : C
- What is the standard frequency of AC power in the United States?** A) 50 Hz B) 60 Hz C) 100 Hz D) 120 Hz **ANSWER : B
- In a series circuit, current is:** A) Different at every point B) Zero at the source C) The same throughout D) Doubled at each resistor ANSWER : C
D) Frequency dependent ANSWER : C
17. What is the function of a transformer? A) To convert AC to DC B) To store electrical energy C) To change AC voltage levels D) To amplify signals **ANSWER : C
- In a parallel circuit, voltage across each component is:** A) Different B) Zero C) The same D) Divided equally **ANSWER : C
- A short circuit occurs when:** A) Resistance is very high B) Current path has near-zero resistance C) Voltage drops to zero D) Capacitance is too large **ANSWER : B
- Which component opposes changes in current flow?** A) Capacitor B) Resistor C) Diode D) Inductor **ANSWER : D
- The color code for gold tolerance on a resistor means:** A) ±1% B) ±5% C) ±10% D) ±20% **ANSWER : B
- What does the term 'ground' refer to in electronics?** A) Positive supply rail
B) Reference point of zero volts C) Highest voltage in a circuit D) AC power source ANSWER : B
23. Which material is commonly used as a semiconductor? A) Copper B) Aluminum C) Silicon D) Iron **ANSWER : C
- The process of converting AC to DC is called:** A) Amplification B) Rectification C) Modulation D) Attenuation **ANSWER : B
- Which gate produces a HIGH output only when all inputs are HIGH?** A) OR gate B) NAND gate C) AND gate D) NOR gate **ANSWER : C
- RMS voltage of a sinusoidal AC wave is approximately:** A) Equal to peak voltage B) Twice the peak voltage C) 0.707 times the peak voltage D) 1.414 times the peak voltage **ANSWER : C
- What is the function of a voltage regulator IC?** A) To amplify voltage B) To maintain a constant output voltage C) To convert voltage to current D) To measure voltage accurately ANSWER : B
D) Infinite ANSWER : D
34. Which type of coupling passes AC signals but blocks DC? A) Direct coupling B) Transformer coupling C) Capacitor coupling D) Resistor coupling **ANSWER : C
- A MOSFET is controlled by:** A) Base current B) Gate voltage C) Emitter current D) Drain resistance **ANSWER : B
- The time constant of an RC circuit equals:** A) R + C B) R / C C) R × C D) C / R **ANSWER : C
- What does PWM stand for?** A) Phase Width Modulation B) Pulse Width Modulation C) Power Watt Measurement D) Periodic Wave Mode **ANSWER : B
- A flip-flop is a type of:** A) Analog amplifier B) Power supply C) Bistable multivibrator D) Frequency filter **ANSWER : C
- The gain of an amplifier is defined as:** A) Input divided by output
B) Output divided by input C) Input plus output D) Output minus input ANSWER : B
40. What is the purpose of a bypass capacitor? A) To block AC signals B) To store DC energy C) To filter high-frequency noise from the supply D) To increase output resistance **ANSWER : C Section 2: Digital Electronics
- How many bits are in one byte?** A) 4 B) 8 C) 16 D) 32 **ANSWER : B
- What is the output of a NOT gate when input is 0?** A) 0 B) 1 C) High impedance D) Undefined **ANSWER : B
- Which number system uses base 16?** A) Binary B) Octal C) Decimal D) Hexadecimal **ANSWER : D
- In TTL logic, a HIGH output is typically:** A) 0 to 0.8V B) 2.4 to 5V
A) CMOS
B) TTL
C) ECL
D) RTL
ANSWER : C
51. The XOR gate produces a HIGH output when: A) Both inputs are LOW B) Both inputs are HIGH C) Inputs are different D) Only input A is HIGH **ANSWER : C
- A priority encoder provides an output corresponding to the:** A) Lowest numbered active input B) Highest numbered active input C) Average of all inputs D) Sum of all inputs **ANSWER : B
- In a JK flip-flop, when J=1 and K=1, the output:** A) Sets to 1 B) Resets to 0 C) Toggles D) Remains unchanged **ANSWER : C
- What does SRAM stand for?** A) Sequential Read-Access Memory B) Static Random-Access Memory C) Synchronous RAM Module D) Serial Read-Address Memory **ANSWER : B
- Which ADC type offers the fastest conversion?** A) Dual slope B) Successive approximation C) Flash ADC D) Sigma-delta ANSWER : C
56. The complement of binary 1011 is: A) 0101 B) 0100 C) 1100 D) 0110 **ANSWER : B
- A tri-state buffer has how many possible output states?** A) 2 B) 3 C) 4 D) 8 **ANSWER : B
- Propagation delay in a logic gate refers to:** A) Time to charge capacitors B) Time from input change to output change C) Signal rise time D) Clock period **ANSWER : B
- An 8-bit DAC can produce how many distinct output levels?** A) 8 B) 16 C) 128 D) 256 **ANSWER : D
- Parity bits are used in digital systems to:** A) Increase data speed B) Detect single-bit errors C) Compress data D) Encrypt information **ANSWER : B
- What is the function of a shift register?** A) To count pulses B) To shift data serially C) To convert analog signals D) To regulate voltage
C) 10001
D) 0000
ANSWER : B
68. A Karnaugh map simplifies: A) Analog waveforms B) Boolean expressions C) Resistor networks D) Filter responses **ANSWER : B
- What does EPROM stand for?** A) Erasable Programmable Read-Only Memory B) Extended Program ROM C) Electronic Parallel ROM Module D) External Processing Memory **ANSWER : A
- In synchronous circuits, all flip-flops change state:** A) Randomly B) Immediately on input change C) On a common clock edge D) Independently **ANSWER : C
- A full adder differs from a half adder by having:** A) A larger output B) A carry-in input C) More speed D) Fewer gates **ANSWER : B
- Which type of counter counts in a non-sequential order?** A) Ripple counter B) Ring counter C) Johnson counter D) Gray code counter **ANSWER : D
- DRAM requires periodic refreshing because:**
A) It uses latches B) Capacitors leak charge C) It is too slow otherwise D) Logic gates degrade ANSWER : B
74. What is the resolution of a 10-bit ADC with a 5V reference? A) About 4.9 mV B) About 9.8 mV C) About 19.5 mV D) About 50 mV **ANSWER : A
- The NAND gate is called a universal gate because:** A) It works at any frequency B) It can implement any logic function C) It requires no power supply D) It has the highest fan-out **ANSWER : B
- What does SPI stand for in microcontroller communication?** A) Serial Peripheral Interface B) Synchronous Parallel Input C) System Program Interface D) Serial Program Instruction **ANSWER : A
- Glitches in combinational logic circuits are caused by:** A) Excessive fan-out B) Different propagation delays along signal paths C) High supply voltage D) Low clock frequency **ANSWER : B
- In two's complement, the negative of a number is found by:** A) Reversing all bits B) Inverting all bits and adding 1 C) Subtracting from 255 D) Shifting bits right ANSWER : B
84. A differentiator circuit produces an output proportional to: A) Integral of input B) Square of input C) Rate of change of input D) Constant of input **ANSWER : C
- In an inverting amplifier, if Rf = 10kΩ and Rin = 1kΩ, the gain is:** A) + B) - 10 C) + D) - 1 **ANSWER : B
- A Colpitts oscillator uses which components for its tank circuit?** A) Two resistors and a capacitor B) Two inductors and a resistor C) Two capacitors and an inductor D) Three resistors **ANSWER : C
- What is the purpose of negative feedback in amplifiers?** A) To increase gain B) To reduce bandwidth C) To improve stability and reduce distortion D) To increase output impedance **ANSWER : C
- The voltage follower circuit has a gain of:** A) - 1 B) 0 C) + D) Variable **ANSWER : C
- Class A amplifiers operate with the transistor:** A) Off for half the cycle B) On for the full cycle C) Switching rapidly on and off D) In saturation always
ANSWER : B
90. A Wheatstone bridge is used to measure: A) Current B) Inductance C) Unknown resistance D) Capacitance **ANSWER : C
- The CMRR of an op-amp measures its ability to:** A) Handle large signals B) Reject signals common to both inputs C) Drive low-impedance loads D) Amplify high frequencies **ANSWER : B
- Which type of filter passes only frequencies below the cutoff?** A) High-pass filter B) Band-pass filter C) Low-pass filter D) Band-stop filter **ANSWER : C
- Thermal runaway in a bipolar transistor amplifier occurs when:** A) Temperature decreases collector current B) Increased temperature increases current, causing further heating C) Bias voltage becomes too high D) Emitter resistance is too large **ANSWER : B
- The 741 op-amp is a classic example of:** A) A discrete transistor amplifier B) A general-purpose integrated circuit op-amp C) A power amplifier IC D) A switching regulator **ANSWER : B
- Which amplifier class has the highest efficiency?** A) Class A B) Class B
A) Drain voltage to gate current B) Drain current to gate voltage C) Source current to drain voltage D) Gate impedance to output power ANSWER : B
102. Bootstrapping in amplifier circuits is used to: A) Reduce gain B) Increase input impedance C) Add negative feedback D) Lower output noise **ANSWER : B
- A phase-locked loop (PLL) is commonly used for:** A) Power regulation B) Memory storage C) Frequency synthesis and demodulation D) Amplifier biasing **ANSWER : C
- What is the purpose of emitter degeneration resistor in BJT amplifier?** A) Increase gain B) Provide DC stability C) Reduce input resistance D) Increase bandwidth **ANSWER : B
- A log amplifier produces an output proportional to:** A) Input squared B) Logarithm of the input C) Derivative of the input D) Square root of the input **ANSWER : B
- Current mirrors are used in ICs to:** A) Invert signals B) Replicate a reference current C) Buffer output stages D) Provide voltage regulation ANSWER : B
107. An integrator circuit produces an output proportional to: A) Rate of change of input B) Amplitude of input C) Integral of input over time D) Frequency of input **ANSWER : C
- What is noise figure in RF amplifiers?** A) Total output noise B) Measure of signal-to-noise ratio degradation C) Input noise voltage D) Gain at high frequencies **ANSWER : B
- A buffer amplifier is used primarily to:** A) Amplify voltage B) Increase frequency C) Match impedances / isolate stages D) Rectify signals **ANSWER : C
- Harmonic distortion in amplifiers is caused by:** A) Phase shift B) Non-linearity of active devices C) Insufficient bandwidth D) High supply voltage **ANSWER : B
- The gain-bandwidth product of an op-amp:** A) Varies with temperature B) Remains approximately constant C) Increases with gain D) Decreases with frequency **ANSWER : B
- What is the Q factor of a resonant circuit?** A) Quality factor indicating selectivity B) Charge stored on capacitor C) Quantity of reactive components D) Quiescent current
