# Electronic Devices (NEET Physics): Questions 38 - 43 of 65

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## Question number: 38

» Electronic Devices » Logic Gates (Or, and, NOT, NAND and NOR)

### Question

What will be the input of A and B for the Boolean expression

### Choices

Choice (4) | Response | |
---|---|---|

a. | 0, 0 | |

b. | 1, 0 | |

c. | 1, 1 | |

d. | 0, 1 |

## Passage

Doping changes the Fermi energy of a semiconductor. Consider silicon, with a gap of 1.11 eV between the top of the valence bond and the bottom of the conduction band. At 300K the Fermi level of the pure material is nearly at the mid-point of the gap. Suppose that silicon is doped with donor atoms, each of which has a state 0.15 eV below the bottom of the silicon conduction band, and suppose further that doping raises the Fermi level to 0.11 eV below the bottom of that band.

## Question number: 39 (1 of 3 Based on Passage) Show Passage

» Electronic Devices » Semiconductors

### Question

For doped silicon, calculate the probability that a state at the bottom of the silicon conduction band is occupied? (e ^{4.254} = 70.38)

### Choices

Choice (4) | Response | |
---|---|---|

a. | 10.5 ⨯ 10 | |

b. | 1.40 ⨯ 10 | |

c. | 14 ⨯ 10 | |

d. | 5.20 ⨯ 10 |

## Question number: 40 (2 of 3 Based on Passage) Show Passage

» Electronic Devices » Semiconductors

### Question

Calculate the probability that a donor state in the doped material is occupied?

### Choices

Choice (4) | Response | |
---|---|---|

a. | 0.008 | |

b. | 0.824 | |

c. | 8.2 | |

d. | 0.08 |

## Question number: 41 (3 of 3 Based on Passage) Show Passage

» Electronic Devices » Semiconductors

### Question

For pure silicon, calculate the probability that a state at the bottom of the silicon conduction band is occupied? (e ^{21.46} = 20.89 ⨯ 10 ^{8})

### Choices

Choice (4) | Response | |
---|---|---|

a. | 4 ⨯ 10 | |

b. | 4.79 ⨯ 10 | |

c. | 5.20 ⨯ 10 | |

d. | 3.42 ⨯ 10 |

## Question number: 42

» Electronic Devices » Logic Gates (Or, and, NOT, NAND and NOR)

### Question

P | Q | X |

0 | 0 | 0 |

0 | 1 | 0 |

1 | 0 | 0 |

1 | 1 | 1 |

### Choices

Choice (4) | Response | |
---|---|---|

a. | NOR | |

b. | OR | |

c. | AND | |

d. | NAND |

## Question number: 43

» Electronic Devices » Junction Transistor

### Question

Which of the following are false?

(1) Common base transistor is commonly used because current gain is maximum

(2) Common collector is commonly used because current gain is maximum

(3) Common emitter is the least used transistor

(4) Common emitter is commonly used because current gain is maximum

Select the correct answers and mark it according to the following codes.

### Choices

Choice (4) | Response | |
---|---|---|

a. | 2 and 4 are correct | |

b. | 1 and 3 are correct | |

c. | 1, 2 and 3 are correct | |

d. | 1 and 2 are correct |