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Electronic devices and circuits
| 1-Dont try to cram or spend more time here just read it fast and cover syllabus then practice MCQ's cheptor of same topic to check your progress. . |
| 2-Wrong options are also given but dont concentrate there, Right answer is in bold format. |
| Q1 ⇒ Work function is the maximum energy required by the fastest electron at 0 K to escape from the metal surface. FALSE [other wrong options] [Discuss in forum] |
| Q2 ⇒ At very high temperatures the extrinsic semi conductors become intrinsic because band to band transition dominants over impurity ionization [other wrong options] [Discuss in forum] |
| Q3 ⇒ Crossover distortion behaviour is characteristic of class B O/P stage [other wrong options] [Discuss in forum] |
| Q4 ⇒ The v-i characteristics of a FET is shown in figure. In which region is the device biased for small signal amplifica BC [other wrong options] [Discuss in forum] |
| Q5 ⇒ The word enhancement mode is associated with MOSFET [other wrong options] [Discuss in forum] |
| Q6 ⇒ For an n-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk (VSB > 0), the threshold voltage VT of the MOSFET will remain unchanged [other wrong options] [Discuss in forum] |
| Q7 ⇒ Which of these has degenerate p and n materials? Tunnel diode [other wrong options] [Discuss in forum] |
| Q8 ⇒ The mean free path of conduction electrons in copper is about 4 x 10-8 m. For a copper block, find the electric field which can give, on an average, 1 eV energy to a conduction electron 2.5 x 107 V/m [other wrong options] [Discuss in forum] |
| Q9 ⇒ Two identical silicon diodes D1 and D2 are connected back to back shown in figure. The reverse saturation current Is of each diode is 10-8 amps and the breakdown voltage VBr is 50 v. Evaluate the voltages VD1 and VD2 dropped across the diodes D1 and D2 assuming KT/q to be 25 - 4.98 V, - 0.017 V [other wrong options] [Discuss in forum] |
| Q10 ⇒ The Hall constant in Si bar is given by 5 x 103 cm3/ coulomb, the hole concentration in the bar is given by 1.25 x 1015/cm3 [other wrong options] [Discuss in forum] |
| Q11 ⇒ The skin depth of copper is found to be 66 mm at 1 MHz at a certain temperature. At the same temperature and at 2 MHz, the skin depth would be approximately 47 μm [other wrong options] [Discuss in forum] |
| Q12 ⇒ One eV = 1.602 x 10-19 joules. TRUE [other wrong options] [Discuss in forum] |
| Q13 ⇒ In an n channel JFET, the gate is p type [other wrong options] [Discuss in forum] |
| Q14 ⇒ The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply of frequency of 5 kHz [other wrong options] [Discuss in forum] |
| Q15 ⇒ An LED has a rating of 2 V and 10 mA. It is used along with 6V battery. The range of series resistance is 400 Ω and above [other wrong options] [Discuss in forum] |
| Q16 ⇒ The derating factor for a BJT transistor is about 2.5 mW/°C [other wrong options] [Discuss in forum] |
| Q17 ⇒ An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ and output resistance of 2.5 kΩ. The input resistance of the current shunt -ve feedback amplifier using the above amplifier with a feedback factor of 0.2 is 1/11 kΩ [other wrong options] [Discuss in forum] |
Q18 ⇒ SCR can be turned on by
1, 2, 3, 4 [other wrong options] [Discuss in forum] |
| Q19 ⇒ A zener diode is used in voltage regulator circuit [other wrong options] [Discuss in forum] |
Q20 ⇒ The threshold voltage of a MOSFET can be lowered by
1 and 3 are correct [other wrong options] [Discuss in forum] |
| Or |