Electronic Devices and Circuits - Section 1 (5)
Electronic Devices and Circuits - Section 1
| 33. | A transistor has two p-n junctions. The batteries should be connected such that |
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Answer: Option C Explanation: Emitter-base junction is forward biased and base collector junction is reverse biased. |
| 34. | The number of doped regions in PIN diode is |
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Answer: Option B Explanation: A PIN diode has p and n doped regions separated by intrinsic layer. |
| 35. | An LED has a rating of 2 V and 10 mA. It is used along with 6V battery. The range of series resistance is |
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Answer: Option D Explanation: |
= 400Ω.| 36. | In an n-p-n transistor, the majority carriers in the base are |
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Answer: Option A Explanation: Emitter is n type and emits electrons which diffuse through the base. |
| 37. | In a p type material the Fermi level is 0.3 eV above valence band. The concentration of acceptor atoms is increased. The new position of Fermi level is likely to be |
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Answer: Option B Explanation: Addition of acceptor atom brings Fermi level closer to valence band. |
| 38. | Ferrite have |
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Answer: Option C Explanation: Ferrite is a low density material of composition with Fe2O3 x O, where x is a bivalent metal, such as Cobart, Ni, Mn. These magnetic materials having very low loss of current and used in high frequency circuit. |
| 39. | When a voltage is applied to a semiconductor crystal then the free electrons will flow. |
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Answer: Option A Explanation: Since electrons are negatively charged they will flow towards positive terminal. |
| 40. | At very high temperatures the extrinsic semi conductors become intrinsic because |
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Answer: Option B Explanation: Covalent bonds are broken. |