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CBSE Class 12 (Science) Semiconductor Electronics: Materials, Devices and Simple Circuits — practice questions
78 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 (Science) Semiconductor Electronics: Materials, Devices and Simple Circuits in the app →Silicon doped with phosphorus becomes which type of semiconductor?Which charge carriers are the majority carriers in an n-type semiconductor?Compared with the host atoms they replace, acceptor atoms have?Donor impurities make a semiconductor n-type by adding what?How does heating affect the conductivity of a semiconductor?As temperature rises, what happens to the conductivity of a metal?Which pair of elements is the most important commercially as semiconductors?How many valence electrons do silicon and germanium atoms have?In which year was the transistor invented?The 1904 cat's-whisker detector was a primitive form of which device?In which year was the integrated circuit developed?In an n-type semiconductor, the Fermi level lies closer to which band?What forms near the boundary when p-type and n-type materials are joined?Which bias lets current flow readily through a p-n junction?Under reverse bias, the current through a junction diode is?In forward bias, the p-side is joined to which terminal?How does reverse bias change the depletion region?Why can electrons cross a forward-biased junction?The potential difference across an unbiased p-n junction is called?Random thermal movement of electrons across a junction is called?Who elucidated the modern theory of p-n junctions?A Zener diode is widely used in circuits as a?A Zener diode regulates voltage while connected in which bias?A Zener diode's junction is made with what level of doping?In silicon diodes breaking down below about 5.6 V, which effect dominates?Below about 5.6 V, the Zener breakdown voltage has what temperature coefficient?Low-voltage Zener breakdown occurs mainly through which process?Zener diodes protect circuits chiefly against which hazard?Junction breakdown stays reversible only if the material does not?A rectifier converts alternating current into?A device converting DC into AC is called a(n)?How many diodes does a basic half-wave rectifier need?In half-wave rectification, the unwanted half of the AC wave is?A full-wave rectifier with a centre-tapped transformer needs how many diodes?What smooths a rectifier's pulsating output into a steady voltage?Why is the mean output voltage of a half-wave rectifier lower?A logic gate performs which kind of function on binary inputs?Logic gates are mainly built from which switching components?Which pair of gates can each build every other logic gate?Which gate gives the negation of the AND operation?By De Morgan's laws, NAND equals which gate with negated inputs?Which gate, fed with negated inputs, behaves exactly like a NOR gate?The Sheffer stroke is another name for which logical operation?Most modern logic gates are fabricated from which devices?Which set names the three regions of a bipolar junction transistor?A bipolar transistor conducts using which charge carriers?Which BJT region is lightly doped and lies between the other two?Which BJT region carries the heaviest doping?A bipolar transistor lets a small injected current control what?In forward-active mode, the base-emitter and base-collector junctions are biased?Common-base current gain of a BJT typically lies between?Why must the base region of a transistor be thin?In an NPN transistor, which layer is sandwiched in the middle?A transistor with an n-type layer between two p-type layers is called?Is the internal structure of a BJT symmetrical between emitter and collector?Which pair invented the first transistor in December 1947?Who invented the junction version of the bipolar transistor in 1948?Compared with silicon, germanium transistors turn on at?Which early transistor material was more prone to thermal runaway?What does an LED do when current flows through it?What determines the colour of light emitted by an LED?In an LED, recombining electrons and holes release energy as?Infrared LEDs are commonly used in which device?Compared with incandescent lamps, LEDs have a?An LED is a transducer turning which energy into light?LEDs are generally restricted to what kind of supply?A solar cell turns light into electricity using which effect?Which French physicist first demonstrated the photovoltaic effect?Which silicon solar cell type has a single-crystal composition?Besides producing power, a solar cell can also serve as a?A semiconductor diode is made of which arrangement?Solar cells and LEDs are essentially built from what?In a varactor diode, reverse bias varies which property?In a Schottky junction, what replaces the n-type semiconductor?Why are field-effect transistors called unipolar?Why is n-type material so called?What does the p in p-type stand for?Besides powering devices, rectifiers can detect what?