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.
| 201. |
During induction heating of metals which of the following is abnormally high? |
| A. | Frequency |
| B. | Voltage |
| C. | Current |
| D. | Power factor |
| Answer» B. Voltage | |
| 202. |
Given a power supply filter circuit, what measurements must be made of determine percentage regulation |
| A. | current through and voltage across the capacitor |
| B. | d.c. load voltage and r.m.s. load voltage |
| C. | current through load and voltage across load resistance |
| D. | number of turns and gauge of secondary winding of transformer |
| Answer» C. current through load and voltage across load resistance | |
| 203. |
A-P type material has an acceptor ion concentration of 1 x 10¹⁶ per cm³. Its intrinsic carrier concentration is 1.48 x 10¹ᴼ/ cm. The hole and electron mobilities are 0.05m²/V-sec and 0.13 m²/V-sec respectively calculate the resistivity of the material |
| A. | 12.5 Ω-cm |
| B. | 1.25 Ω-cm |
| C. | 0.125 Ω-cm |
| D. | 125 Ω-cm |
| Answer» C. 0.125 Ω-cm | |
| 204. |
The voltage across a zener diode |
| A. | is constant in forward direction |
| B. | is constant in reverse direction |
| C. | is constant in both forward and reverse directions |
| D. | none of the above |
| Answer» C. is constant in both forward and reverse directions | |
| 205. |
In an n-p-n transistor, the majority carriers in the base are |
| A. | electrons |
| B. | holes |
| C. | both holes and electrons |
| D. | either holes or electrons |
| Answer» B. holes | |
| 206. |
Electrical contact materials used in switches, brushes and relays must possess |
| A. | high thermal conductivity and high melting point |
| B. | low thermal conductivity and low melting point |
| C. | high thermal conductivity and low melting point |
| D. | low thermal conductivity and high melting point |
| Answer» B. low thermal conductivity and low melting point | |
| 207. |
At absolute zero temperature a semiconductor behaves like |
| A. | an insulator |
| B. | a super conductor |
| C. | a good conductor |
| D. | a variable resistor |
| Answer» B. a super conductor | |
| 208. |
In a JFET VDS exceeds the rated value. Then it operates in |
| A. | active region |
| B. | ohmic region |
| C. | cut off region |
| D. | either cut off or active region |
| Answer» D. either cut off or active region | |
| 209. |
A silicon (PN) junction at a temperature of 20°C has a reverse saturation current of 10 pico Ampere. The reverse saturation current at 40°C for the same bias is approximately. |
| A. | 30 pA |
| B. | 40 pA |
| C. | 50 pA |
| D. | 60 pA |
| Answer» C. 50 pA | |
| 210. |
The amount of photoelectric emission current depends on the frequency of incident light. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 211. |
In a forward biased p-n junction current enters p material as hole current and leaves n material as electron current of the same magnitude. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 212. |
Assertion (A): In a Schottky diode the reverse recovery time is almost zero.Reason (R): A Schottky diode has aluminium silicon junction. |
| 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 | |
| 213. |
Typical value of reverse current in a semiconductor diode is |
| A. | 1 A |
| B. | 0.1 A |
| C. | 1 μA |
| D. | 0.1 μA |
| Answer» E. | |
| 214. |
Assertion (A): The behaviour of FET is similar to that of a pentode.Reason (R): FETs and vacuum triode are voltage controlled devices. |
| 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 | |
| 215. |
For signal diodes the PIV rating is usually in the range |
| A. | 1 V to 10V |
| B. | 10 V to 30V |
| C. | 30 V to 150V |
| D. | 150 V to 400V |
| Answer» D. 150 V to 400V | |
| 216. |
A varactor diode is used for |
| A. | tuning |
| B. | rectification |
| C. | amplification |
| D. | rectification and amplification |
| Answer» B. rectification | |
| 217. |
Which of the following materials has the highest electrical conductivity? |
| A. | Steel |
| B. | Silver |
| C. | Aluminium |
| D. | Zinc |
| Answer» C. Aluminium | |
| 218. |
The primary function of a clamper circuit is to |
| A. | suppress variations in signal voltage |
| B. | raise +ve half cycle to the signal |
| C. | Lower -ve half cycle of the signal |
| D. | introduce a dc level into an a.c. signal |
| Answer» C. Lower -ve half cycle of the signal | |
| 219. |
Germanium and Si phosphorus have their maximum spectral response in the |
| A. | infrared region |
| B. | ultraviolet region |
| C. | visible region |
| D. | X-ray region |
| Answer» C. visible region | |
| 220. |
In intrinsic semiconductor magnitude of free electron and hole concentrations are equal. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 221. |
Consider the following statements about diamagnetic material and diamagnetism. 1. The materials have negative magnetic susceptibility.2. At very low temperature diamagnetic materials. Which of the statements given above is/are correct? |
| A. | 1 only |
| B. | 2 only |
| C. | Both 1 and 2 |
| D. | neither 1 nor 2 |
| Answer» B. 2 only | |
| 222. |
An enhancement mode MOSFET is on when the gate voltage is |
| A. | zero |
| B. | positive |
| C. | high |
| D. | more threshold value |
| Answer» E. | |
| 223. |
A voltage of 9 V is applied in forward direction to a semiconductor diode in series with a load resistance of 1000 Ω. The voltage across the load resistance is zero. It indicates that |
| A. | diode is short circuited |
| B. | diode is open circuited |
| C. | resistor is open circuited |
| D. | diode is either o.c or s.c |
| Answer» C. resistor is open circuited | |
| 224. |
In a P type silicon sample, the hole concentration is 2.25 x 10¹⁵ / cm³. If the intrinsic carrier concentration is 1.5 x 10¹ᴼ/ cm³ the electron concentration is |
| A. | zero |
| B. | 10¹ᴼ/cm³ |
| C. | 10⁵/cm³ |
| D. | 1.5 x 10²⁵/cm³ |
| Answer» D. 1.5 x 10²⁵/cm³ | |
| 225. |
An n channel depletion type MOSFET has |
| A. | lightly doped p substrate and highly doped n source and drain |
| B. | highly doped p substrate and highly doped n source and drain |
| C. | highly doped p substrate and lightly doped n source and drain |
| D. | lightly doped n substrate and highly doped n source and drain |
| Answer» B. highly doped p substrate and highly doped n source and drain | |
| 226. |
Assertion (A): In a BJT, αdc is about 0.98.Reason (R): In a BJT, recombination in base region is high. |
| 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 | |
| 227. |
Hay bridge is suitable for measuring inductance of which one of the following inductors? |
| A. | Having Q value less than 10 |
| B. | Having Q value greater than 10 |
| C. | Having any value of Q |
| D. | Having phase angle of reactance very large |
| Answer» C. Having any value of Q | |
| 228. |
The conductivity of a semiconductor crystal due to any current carrier is not proportional to |
| A. | mobility of the carrier |
| B. | effective density of states in the conduction band |
| C. | electronic charge |
| D. | surface states in the semiconductor |
| Answer» B. effective density of states in the conduction band | |
| 229. |
A d.c. power supply has an open circuit voltage of 100 V. When the full load current is drawn, the output drops to 80 V. The percentage voltage regulation is |
| A. | 97.25% |
| B. | 75% |
| C. | 50% |
| D. | 25% |
| Answer» E. | |
| 230. |
Assertion (A): When a zener diode breakdown, occurs the voltage across it is constant.Reason (R): The upper limit of zener current is determined by power handling capacity. |
| 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 | |
| 231. |
In N-type semiconductor |
| A. | electrons are majority carriers while holes are minority carriers |
| B. | electrons are majority carriers while holes are majority carriers |
| C. | both electrons as well as holes are majority carriers |
| D. | both electrons as well as holes are minority carriers |
| Answer» B. electrons are majority carriers while holes are majority carriers | |
| 232. |
Which of the following material can be used in cable shields? |
| A. | Copper |
| B. | Aluminium |
| C. | Cast iron |
| D. | Lead |
| Answer» E. | |
| 233. |
In LED the radiation is in |
| A. | visible region |
| B. | infrared region |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» E. | |
| 234. |
The passage of current in an electrolyte is due to the movement of |
| A. | electrons |
| B. | molecules |
| C. | atoms |
| D. | ions |
| Answer» E. | |
| 235. |
If Vr is the reverse voltage across a graded P-N Junction, then the junction capacitance cj is proportional to |
| A. | (Vr)² |
| B. | (Vr)ⁿ |
| C. | (Vr)¯ⁿ |
| D. | (Vr)⅔ |
| Answer» C. (Vr)¯ⁿ | |
| 236. |
In energy band diagram of n type semiconductor, the donor energy level is |
| A. | in valence band |
| B. | in conduction band |
| C. | slightly above valence band |
| D. | slightly below conduction band |
| Answer» E. | |
| 237. |
The early effect in a BJT is caused by |
| A. | fast turn on |
| B. | fast turn off |
| C. | large collector base reverse bias |
| D. | large emitter base forward bias |
| Answer» D. large emitter base forward bias | |
| 238. |
Assertion (A): The reverse current in a p-n junction is nearly constant.Reason (R): The reverse breakdown voltage of a p-n diode depends on the extent of doping. |
| 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 | |
| 239. |
How is an N-channel junction Field Effect Transistor operated as an amplifier? |
| A. | With a forward bias gate source junction |
| B. | With a reverse bias gate-source junction |
| C. | With a open gate source junction |
| D. | With a shorted gate source junction |
| Answer» C. With a open gate source junction | |
| 240. |
If a sample of germanium and a sample of Si have the impurity density and are kept at room temperature then |
| A. | both will have equal value of resistivity |
| B. | both will have equal -ve resistivity |
| C. | resistivity of germanium will be higher than that of silicon |
| D. | resistivity of Si will be higher than of germanium |
| Answer» E. | |
| 241. |
Which of the following elements act as donor impurities? 1. Gold2. Phosphorus3. Boron4. Antimony5. Arsenic6. IndiumSelect the correct answer using the codes given below: |
| A. | 1, 2, 3 |
| B. | 1, 2, 4, 6 |
| C. | 3, 4, 5, 6 |
| D. | 1, 4, 5 |
| Answer» E. | |
| 242. |
What is meant by "continuous collector current" in BJT? |
| A. | Maximum collector current |
| B. | Current at Quiescent condition |
| C. | Leakage current |
| D. | Junction Capacitance charging and discharging current |
| Answer» B. Current at Quiescent condition | |
| 243. |
Consider the following statement: At finite temperature, magnetic dipoles in a material are randomly oriented giving low magnetization. When magnetic field H is applied, the magnetization? 1. Increases with H2. Decreases with H3. Decreases with temp for constant H Which of the statement given above is/are correct? |
| A. | 1 |
| B. | 2 |
| C. | 2, 3 |
| D. | 1 and 3 |
| Answer» E. | |
| 244. |
At very high temperatures the extrinsic semi conductors become intrinsic because |
| A. | drive in diffusion of dopants and carriers |
| B. | band to band transition dominants over impurity ionization |
| C. | impurity ionization dominants over band to band transition |
| D. | band to band transition is balanced by impurity ionization |
| Answer» C. impurity ionization dominants over band to band transition | |
| 245. |
Assertion (A): FET is a unipolar device.Reason (R): BJT is bipolar device. |
| 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 | |
| 246. |
Assertion (A): The hybrid π model of a transistor can be reduced to h parameter model and vice versa.Reason (R): Hybrid π and h parameter models are interrelated as both of them describe the same device. |
| 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 | |
| 247. |
In commercial electron tubes the current produced by the cathode at 1000 K is about |
| A. | 0.01 A per cm² of cathode surface |
| B. | 0.1 A per cm² of cathode surface |
| C. | 1 A per cm² of cathode surface |
| D. | 5 A per cm² of cathode surface |
| Answer» C. 1 A per cm² of cathode surface | |
| 248. |
In a bipolar junction transistor αdc = 0.98, ICO= 2 μA and 1B = 15 μA. The collector current IC is |
| A. | 635 mA |
| B. | 735 mA |
| C. | 835 mA |
| D. | 935 mA |
| Answer» C. 835 mA | |
| 249. |
The types of carriers in a semiconductor are |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 250. |
The current gain of a BJT is |
| A. | gm r0 |
| B. | gm/r0 |
| C. | gm rp |
| D. | gm/rp |
| Answer» D. gm/rp | |