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TS EAPCET (Engineering) Semiconductor Electronics: Materials, Devices and Simple Circuits — practice questions
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Practice TS EAPCET (Engineering) Semiconductor Electronics: Materials, Devices and Simple Circuits in the app →In which year was the transistor discovered, after which vacuum tubes gave way?In a vacuum tube, the electrons that carry the current are supplied by:Compared with vacuum tubes, semiconductor devices typically have:Galena, a crystal once used to detect radio waves, is chemically:Which pair of elements are elemental semiconductors?Gallium arsenide (GaAs) is an example of a:In metallic conductors, the conduction band and valence band:For a germanium atom, the outermost electrons lie in which orbit?At absolute zero, the valence band of pure silicon is:A solid behaves as an insulator when its energy band gap is roughly:In the diamond-like lattice of silicon, each atom has how many nearest neighbours?The shared electron pairs between neighbouring Si atoms form a:Under an applied electric field, holes in a semiconductor move towards the:At thermal equilibrium in a semiconductor, the rate of carrier generation is:C, Si and Ge share a lattice type, yet carbon is an insulator because its:Doping a pure semiconductor usually adds impurity at a level of a few:Which element is a pentavalent dopant for silicon?Which dopant turns germanium into a p-type semiconductor?The energy needed to free the fifth electron of a donor atom in silicon is about:Diamond, a crystalline form of carbon, has an energy gap of about:Tin is a group IV element, yet it is a metal because its energy gap is:A pentavalent impurity in silicon is called a donor because it:In n-type Si, the number of electrons supplied by donor atoms depends mainly on the:Donor doping lowers the hole count in Si because:In p-type Si, an ionised acceptor atom carries an effective charge that is:How many holes does each trivalent acceptor atom contribute?In the band structure of n-type silicon, the donor level lies:A crystal with 5 x 10^28 Si atoms per m^3 gets 1 ppm of arsenic. Its electron density is about:Why can't pressing p and n slabs together form a junction?The two key processes that occur while a p-n junction forms are:An electron diffusing from n-side to p-side leaves behind:The electric field in the depletion region of a p-n junction points:The motion of charge carriers caused by an electric field is called:At equilibrium, the net current through an unbiased p-n junction is:Forward biasing a p-n junction diode means connecting:A diode with built-in potential V0 is forward biased by V. Its effective barrier height is:Under forward bias, the depletion layer of a p-n junction:Under forward bias, carriers crossing to the opposite side is:Below breakdown, a diode's reverse current is limited by the:The reverse voltage at which a diode's reverse current rises sharply is the:If a diode's current is allowed to exceed its rated value, the diode is destroyed by:The cut-in voltage of a silicon junction diode is about:A reverse biased diode's tiny, steady current is called the:The dynamic resistance of a diode is defined as the ratio of:A diode's voltage rises from 0.7 V to 0.8 V as its current goes from 10 mA to 20 mA. Its rd is:A reverse biased diode passes 1 microampere at 10 V. Its reverse resistance is:In a half-wave rectifier, output appears across the load only while the diode is:A rectifier diode's reverse breakdown voltage must be:A two-diode full-wave rectifier needs a secondary that is:A full-wave rectifier that needs no centre-tap transformer uses how many diodes?To smooth a rectifier's output, a filter capacitor is connected:Capacitor input filters use large capacitors mainly to make the:With a capacitor input filter, the dc output voltage is close to the rectified:In GaAs, the semiconductor type can also be set by altering the:Television CRT monitors, based on vacuum tube principles, have been replaced by:The invention of the p-n junction in 1939 is usually credited to:Who set out the modern theory of p-n junctions in the classic 1950 book on electrons and holes?Solar cells and light-emitting diodes are, at heart, simply:A reverse biased p-n junction usually breaks down through which two processes?A varactor diode uses its reverse bias voltage to vary its:A device that converts alternating current into direct current is a:A device that converts direct current into alternating current is called:How many diodes does half-wave rectification of a single-phase supply need?Mathematically, ideal full-wave rectification of a signal corresponds to the:For equal output, a centre-tap rectifier's secondary needs, versus a bridge:The forward voltage drop of a Schottky diode is typically around:A silicon bridge rectifier gets a 12 V peak ac input. Its peak output is about:With 50 Hz mains, the main ripple in a full-wave rectifier's output is at:Compared with a capacitor-input filter, a choke-input filter gives:The release of electrons from a heated filament, called the Edison effect, is:In gas heating systems, flame rectification is used to: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?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?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?The potential difference across an unbiased p-n junction is called?A Zener diode is widely used in circuits as a?A Zener diode regulates voltage while connected in which bias?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?A rectifier converts alternating current into?