MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 869 Mcqs, each offering curated multiple-choice questions to sharpen your BITSAT knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
In the vacuum diode equation ib = keb^1.5, the current is |
| A. | temperature limited current |
| B. | space charge limited current |
| C. | any of the above |
| D. | none of the above |
| Answer» C. any of the above | |
| 102. |
In p channel JFET, VGS is positive. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 103. |
The conductivity of germanium increases by about 6 percent per degree increase in temperature. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 104. |
The range of visible light is |
| A. | 300 to 2000 Å |
| B. | 200 - 4000 Å |
| C. | 4000 to 7700 Å |
| D. | more than 10000 Å |
| Answer» D. more than 10000 Å | |
| 105. |
High purity copper is obtained by |
| A. | rolling casting |
| B. | casting |
| C. | electrolytic refining |
| D. | induction heating |
| Answer» D. induction heating | |
| 106. |
Atomic number of germanium is |
| A. | 24 |
| B. | 28 |
| C. | 32 |
| D. | 36 |
| Answer» D. 36 | |
| 107. |
Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resulting electric field inside the speciment will be in |
| A. | direction normal to both current and magnetic field |
| B. | the direction of current |
| C. | direction antiparallel to magnetic field |
| D. | an arbitrary direction depend upon conductivity |
| Answer» B. the direction of current | |
| 108. |
In a semiconductor avalanche breakdown occurs when |
| A. | reverse bias exceeds the limiting value |
| B. | forward bias exceeds the limiting value |
| C. | forward current exceeds the limiting value |
| D. | potential barrier is reduced to zero |
| Answer» B. forward bias exceeds the limiting value | |
| 109. |
Between which regions does BJT act like switch? |
| A. | Cut off and saturation |
| B. | Cut off and forward active |
| C. | Forward active and cut off |
| D. | Saturation and active |
| Answer» B. Cut off and forward active | |
| 110. |
The reverse saturation current depends on the reverse bias. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 111. |
An n channel JFET has IDS whose value is |
| A. | maximum for VGS = 0 and minimum for VGS negative and large |
| B. | minimum for VGS = 0 and maximum for VGS negative and large |
| C. | maximum for VGS = 0 and minimum for VGS positive and large |
| D. | minimum for VGS = 0 and maximum for VGS positive and large |
| Answer» B. minimum for VGS = 0 and maximum for VGS negative and large | |
| 112. |
The rating of a transformer to deliver 100 watts of D.C. power to a load under half wave rectifier will be nearly |
| A. | 1 kVA |
| B. | 350 VA |
| C. | 175 VA |
| D. | 108 VA |
| Answer» C. 175 VA | |
| 113. |
The kinetic energy of photoelectrons emitted by a photo sensitive surface depends on |
| A. | intensity of the incident radiation |
| B. | wavelength of the incident radiation |
| C. | surface conditions of the surface |
| D. | angle of incidence of radiation |
| Answer» C. surface conditions of the surface | |
| 114. |
Assertion (A): Two transistors one n-p-n and the other p-n-p are identical in all respects (doping, construction, shape, size). The n-p-n transistor will have better frequency response.Reason (R): The electron mobility is higher than hole mobility. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 115. |
In a conductor the conduction and valence bands overlap |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 116. |
Photoconductive devices uses |
| A. | metallic conductors |
| B. | good quality insulators |
| C. | semiconductors |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 117. |
In an n channel JFET, VGS = VGS(off). Then |
| A. | ID is zero |
| B. | ID may be zero or positive |
| C. | ID is positive |
| D. | ID may be zero or negative |
| Answer» B. ID may be zero or positive | |
| 118. |
In all metals |
| A. | conductivity decreases with increase in temperature |
| B. | current flow by electrons as well as by holes |
| C. | resistivity decreases with increase in temperature |
| D. | the gap between valence and conduction bands is small |
| Answer» B. current flow by electrons as well as by holes | |
| 119. |
Donor energy level is n type semiconductor is very near valence band. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 120. |
In fabricating silicon BJT in ICs by the epitaxial process, the number of diffusions used is usually |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 6 |
| Answer» E. | |
| 121. |
At a P-N junction, the potential barrier is due to the charges on either side of the junction, which consists of |
| A. | fixed donor and acceptor ions |
| B. | majority carriers only |
| C. | minority carriers only |
| D. | both majority and minority carriers |
| Answer» B. majority carriers only | |
| 122. |
The value of a in a transistor |
| A. | is always equal to 1 |
| B. | is less than 1 but more than 0.9 |
| C. | is about 0.4 |
| D. | is about 0.1 |
| Answer» C. is about 0.4 | |
| 123. |
Dielectric strength of polythene is around |
| A. | 10 kV/mm |
| B. | 40 kV/mm |
| C. | 100 kV/mm |
| D. | 140 kV/mm |
| Answer» C. 100 kV/mm | |
| 124. |
The threshold voltage of a MOSFET can be lowered by 1. using thin gate oxide2. reducing the substrate concentration3. increasing the substrate concentration. Of the above statement |
| A. | 3 alone is correct |
| B. | 1 and 2 are correct |
| C. | 1 and 3 are correct |
| D. | 2 alone is correct |
| Answer» D. 2 alone is correct | |
| 125. |
When a p-n-p transistor is properly biased to operate in active region the holes from emitter. |
| A. | diffuse through base into collector region |
| B. | recombine with electrons in base |
| C. | recombine with electrons in emitter |
| D. | none of the above |
| Answer» B. recombine with electrons in base | |
| 126. |
The temperature of cathode is increased from 2500K to 2600K. The increase in thermionic emission current is about |
| A. | 0.1% |
| B. | 4% |
| C. | 50% |
| D. | 150% |
| Answer» E. | |
| 127. |
The probability giving distribution of electrons over a range of allowed energy levels is known as |
| A. | Maxwell's Distribution |
| B. | Fermi-Dirac Distribution |
| C. | Richardson Dushman Distribution |
| D. | none of the above |
| Answer» C. Richardson Dushman Distribution | |
| 128. |
In an n channel JFET, the gate is |
| A. | n type |
| B. | p type |
| C. | either n or p |
| D. | partially n & partially p |
| Answer» C. either n or p | |
| 129. |
Assertion (A): In an n-p-n transistor as the electrons enter the collector region, they are accelerated towards the collector terminal.Reason (R): Emitter base junction in BJT is forward biased. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 130. |
The merging of a hole and an electron is called |
| A. | recombination |
| B. | covalent bonding |
| C. | thermal union |
| D. | none of the above |
| Answer» B. covalent bonding | |
| 131. |
Mobility is directly proportional to Hall coefficient. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 132. |
One eV = 1.602 x 10¯¹⁹ joules. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 133. |
In n channel JFET, the gate voltage is made more negative |
| A. | the channel width will increase |
| B. | the channel width will decrease |
| C. | the channel width and drain current will decrease |
| D. | the channel width will decrease and drain current will increase |
| Answer» D. the channel width will decrease and drain current will increase | |
| 134. |
The concentration of minority carriers in a semiconductor depends mainly on |
| A. | the extent of doping |
| B. | temperature |
| C. | the applied bias |
| D. | none of the above |
| Answer» C. the applied bias | |
| 135. |
The intrinsic carrier concentration of silicon sample at 300 K is 1.5 x 10¹⁶/m³. If after doping, the number of majority carriers is 5 x 10²ᴼ/m³. The minority carrier density is |
| A. | 4.5 x 10¹¹/m³ |
| B. | 3.33 x 10⁴/m³ |
| C. | 5 x 10²ᴼ/m³ |
| D. | 3 x 10¯⁵/m³ |
| Answer» B. 3.33 x 10⁴/m³ | |
| 136. |
The depletion layer consists of immobile ions. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 137. |
An inductor filter has a ripple that __________ with load resistance and consequently is used only with relatively __________ load currents. |
| A. | decreases, low |
| B. | decreases, high |
| C. | increases, low |
| D. | increases, high |
| Answer» E. | |
| 138. |
In a photodiode the current is due to |
| A. | majority carriers |
| B. | minority carriers |
| C. | both majority and minority carriers |
| D. | either (a) or (b) |
| Answer» C. both majority and minority carriers | |
| 139. |
A CMOS amplifier when compared to an N-channel. MOSFET, has the advantage of |
| A. | higher cut off frequency |
| B. | higher voltage gain |
| C. | higher current gain |
| D. | lower current drain from the power supply, there by less dissipation |
| Answer» B. higher voltage gain | |
| 140. |
The product kT (where k is Boltzmann's constant and T is absolute temperature) at room temperature is about |
| A. | 0.051 eV |
| B. | 0.026 eV |
| C. | 0.01 eV |
| D. | 0.001 eV |
| Answer» C. 0.01 eV | |
| 141. |
The spins in a ferrimagnetic material are |
| A. | all aligned parallel |
| B. | partially aligned antiparallel without exactly cancelling out sublattice magnetisation |
| C. | randomly oriented |
| D. | all aligned antiparallel such that the sublattice cancels out exactly |
| Answer» C. randomly oriented | |
| 142. |
At room temperature, the current in the, intrinsic semiconductor is due to |
| A. | holes |
| B. | electrons |
| C. | ions |
| D. | holes and electrons |
| Answer» E. | |
| 143. |
Assertion (A): Silicon is less sensitive to changes in temperature than germanium.Reason (R): It is more difficult to produce minority carriers in silicon than in germanium. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 144. |
Resistivity of carbon is around |
| A. | 10 to 70 m-ohm-cm |
| B. | 80 to 130 m-ohm-cm |
| C. | 800 to 1300 m-ohm-cm |
| D. | 8000 to 13000 m-ohm-cm |
| Answer» D. 8000 to 13000 m-ohm-cm | |
| 145. |
Calculate the stability factor and change in IC from 25°C to 100°C for, β = 50, RB/ RE = 250, ΔIC0 = 19.9 nA for emitter bias configuration. |
| A. | 42.53, 0.85 μA |
| B. | 40.91, 0.58 μA |
| C. | 40.91, 0.58 μA |
| D. | 41.10, 0.39 μA |
| Answer» B. 40.91, 0.58 μA | |
| 146. |
The amount of time between the creation and disappearance of a hole in an intrinsic semiconductor material is called |
| A. | life cycle |
| B. | recombination time |
| C. | life time |
| D. | half life |
| Answer» D. half life | |
| 147. |
With increasing temperature, the electrical conductivity of metals |
| A. | increases |
| B. | decreases |
| C. | increases first and then decreases |
| D. | remains unaffected |
| Answer» C. increases first and then decreases | |
| 148. |
The energy of one quantum of light equal to hf. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 149. |
If aac for transistor is 0.98 then βac is equal to |
| A. | 51 |
| B. | 49 |
| C. | 47 |
| D. | 45 |
| Answer» C. 47 | |
| 150. |
In intrinsic semiconductor the increase in conductivity per degree increase in temperature is about |
| A. | 2% |
| B. | 6% |
| C. | 15% |
| D. | 25% |
| Answer» C. 15% | |