CBSE Class 12 Semiconductors — practice questions
58 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 Semiconductors in the app →An intrinsic semiconductor at room temperature has:Doping silicon with a pentavalent element like phosphorus creates a semiconductor in which:A p-n junction diode is forward biased when:The output of an AND gate is HIGH only when:On the basis of the energy-band picture, materials are classified by the size of the energy gap $E_g$ between At absolute zero ($T = 0\,\text{K}$), a pure intrinsic semiconductor behaves like a(n)In a pure intrinsic semiconductor at temperature $T > 0\,\text{K}$, the relation between the number density ofPure silicon is doped with a small amount of PHOSPHORUS (a pentavalent element from group 15). The resulting sIf silicon is doped with a TRIVALENT impurity such as boron (or indium), the resulting semiconductor isWhen a p-n junction is formed (BEFORE any external bias is applied), a thin region near the junction develops When a p-n junction diode is subjected to a FORWARD BIAS (p-side connected to the positive terminal of the batUnder REVERSE BIAS, an IDEAL p-n junction diode would carry zero current. A real diode, however, carries a verAn intrinsic silicon sample at room temperature has $n_i \approx 1.5\times 10^{16}\,\text{m}^{-3}$. After dopiThe barrier (built-in) potential of an unbiased silicon p-n junction at room temperature is approximatelyA semiconductor diode is connected with its p side at $+5\,\text{V}$ and its n side at $+3\,\text{V}$. Which bA p-n junction in REVERSE BIAS is irradiated with light of photon energy slightly GREATER than the band gap ofThe band holding the valence electrons is called the:The band just above the valence band is the:The energy separation between the two bands is called the:Deliberate addition of an impurity to a semiconductor is called:A doped semiconductor is described as:In an intrinsic semiconductor, electrons and holes are:Doping with a pentavalent atom gives which type?Doping with a trivalent atom gives which type?A pentavalent impurity is known as a:A trivalent impurity is known as an:In an n-type semiconductor, the majority carriers are:In a p-type semiconductor, the majority carriers are:One acceptor atom gives how many holes?Conductivity of an intrinsic semiconductor depends on its:A material with a band gap above three electron volts is an:A material with a band gap below three electron volts is a:A material behaves as a metal when the two bands:In an n-type semiconductor, the minority carriers are:A junction diode is described as a device with how many electrodes?Holes exist as vacant levels created in the:The two elemental semiconductors studied here are germanium and:In an isolated atom, an electron's energy is fixed by its:Inside a crystal, no two electrons see the same pattern of:Closely spaced energy levels in a solid form what are called:Which band contains the energy levels of valence electrons:The band lying above the valence band is called the:With no external energy supplied, the valence electrons all sit in the:In the absence of excitation, the conduction band is normally:When the conduction band overlaps the valence band, the material is a:If a gap leaves the valence electrons all bound, the material is an:At room temperature, the conductivity of an intrinsic semiconductor is:The conductivity of a semiconductor is improved by adding:The impurity added to a semiconductor is measured in parts per:A semiconductor with added impurity is called:The deliberate addition of an impurity is called:Atoms of the added impurity go by which name:A dopant must be chosen so that it does not distort the:For a dopant not to distort the lattice, its atoms must be of nearly the same:Silicon and germanium are described as elements that are:How many types of dopant are used with silicon or germanium?Arsenic, antimony and phosphorus are dopants that are:Indium, boron and aluminium are dopants that are: