Free Electronics and Devices MCQs with Answers

• A. create more electrical noise
• B. are likely to melt under excessive eddy current heat
• C. consume more power
• D. exhibit unwanted inductive and capacitive effects

Explanation: The turns of a wire-wound resistor form a coil, giving it unwanted inductance and inter-turn capacitance.

• A. can dissipate considerable amount of power
• B. can act as energy storage devices
• C. connecting them in parallel in¬creases the total value
• D. oppose sudden changes in voltage

Explanation: A resistor converts electrical energy into heat and can therefore dissipate considerable power.

• A. Thermocouple
• B. Photovoltaic cell
• C. Solar cell
• D. Photoelectric cell

Explanation: A thermocouple mainly converts a temperature difference into a small voltage for measurement, rather than serving as a practical power…

• A. non-linear circuit
• B. linear circuit
• C. bilateral circuit
• D. none of the above

Explanation: A semiconductor diode has a nonlinear voltage-current characteristic, so a circuit containing it is nonlinear even if its resistors and…

• A. Inductance
• B. Condenser
• C. Wire wound resistor
• D. Transistor

Explanation: A transistor is nonlinear because its current-voltage characteristics are not proportional over its operating range.

• A. 0.5 volt
• B. 1 volt
• C. 1.8 volt
• D. 1. 5 volt

Explanation: A single silicon solar cell produces approximately 0.5 to 0.6 V under normal operation, so 0.5 V is the closest option.

• A. aluminum
• B. Germanium
• C. silicon
• D. scandium

Explanation: Silicon is widely used for solar cells because it is a semiconductor with suitable photovoltaic properties and abundant availability.

• A. Compounds of silver
• B. Liquid metals
• C. Metallic alloys
• D. Electrolytes

Explanation: Electrolytes generally have a negative temperature coefficient of resistance because increased temperature improves ionic mobility and…

• A. lead and zinc
• B. chromium and vanadium
• C. nickel and chromium
• D. copper and silver

Explanation: Nichrome is primarily an alloy of nickel and chromium, selected for its high resistivity, high melting point, and oxidation resistance.

• A. 3
• B. 4
• C. 6
• D. 7

Explanation: Carbon has atomic number 6, with electron configuration 2, 4. Therefore, four electrons occupy its outermost orbit.

• A. for inductive circuits
• B. to supress surges
• C. as heating elements
• D. as current stabilizers

Explanation: A voltage-dependent resistor, or varistor, sharply reduces its resistance when the voltage becomes excessive.

• A. Charcoal
• B. Silicon Carbide
• C. Nichrome
• D. Graphite

Explanation: Varistors are commonly manufactured from silicon carbide or metal oxides such as zinc oxide.

• A. conductance
• B. resistance
• C. reluctance
• D. thermal conductivity

Explanation: Conductance is the reciprocal of resistance, so a material with low resistance has high conductance.

• A. Varistors
• B. Thermistor
• C. Semi-conductors
• D. Variable resistors

Explanation: Semiconductors have conductivity between that of good conductors and insulators.

• A. has lower wattage rating
• B. has higher wattage rating
• C. has large number of turns
• D. offers large number of tapping

Explanation: A rheostat is intended to control relatively larger current and therefore generally has a higher power rating than a potentiometer.

• A. semi-conductor
• B. super-conducto
• C. compound
• D. insulator

Explanation: A compound is formed when atoms of two or more different elements combine chemically, so its molecules contain dissimilar atoms.

• A. any electron from the orbit
• B. first electron from the orbit
• C. second electron from the orbit
• D. third electron from the orbit

Explanation: After each electron is removed, the ion becomes more positively charged and holds its remaining electrons more strongly.

• A. it takes in proton
• B. its atoms are removed
• C. it gives away electrons
• D. it gives away positive charge

Explanation: Electrons are transferred when glass is rubbed with silk; the glass loses electrons and becomes positively charged.

• A. collisions between conduction electrons and atoms
• B. the release of conduction electrons from parent atoms
• C. mutual collisions between metal atoms
• D. mutual collisions between conducting electrons

Explanation: Conduction electrons transfer energy to the metal lattice through collisions with atoms.

• A. zero
• B. negative
• C. positive
• D. about 2 ohms per degree

Explanation: The filament is made of a metal with a positive temperature coefficient, so its resistance rises as it becomes hot.