Courses

# Test: PN Diode

## 10 Questions MCQ Test Physics Class 12 | Test: PN Diode

Description
This mock test of Test: PN Diode for Class 12 helps you for every Class 12 entrance exam. This contains 10 Multiple Choice Questions for Class 12 Test: PN Diode (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: PN Diode quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: PN Diode exercise for a better result in the exam. You can find other Test: PN Diode extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

### A photodiode is used preferably in

Solution:

Photo diode is used to detect light.
In a reverse biased condition, the width of the depletion region increases as the applied reverse bias voltage increases across the diode. So, by applying a larger voltage, more of the incident photons are converted to electric current thereby increasing the efficiency.
In forward biased conditions, the width of the depletion region decreases so only a small portion of the incident photons get converted to electric current and hence the efficiency is less.
Hence photo diode in reverse biased condition detects light.

QUESTION: 2

### When a forward bias is applied to a p-n junction, it

Solution:

When a forward bias is applied to a p-n junction it lowers the value of potential barrier. In the case of a forward bias the potential barrier opposes the applied voltage. Hence the potential barrier across the junction gets reduced.

QUESTION: 3

### Which of the following is true for a forward-biased diode?

Solution:

There are two types of ions -anions are the - ve ones & cations are the +ve ones.As we know current flow from +ve to - ve, so During electrolysis or forward biasing anions move to anodes that are +ve in nature whereas cations move to cathodes which are -ve in nature.

QUESTION: 4

The diode current depends on which of the following:

Solution:

The diode will reach its trigger point at lower voltage with rise in ambient temp, and at higher voltage for lower temp. As increased in temp, it accounts larger diode current than its previous current. When we talk about REVERSE SATURATION CURRENT, yes the diode current is dependable on it, because the (IS) i.e., reverse saturation current mainly depends on temp.

QUESTION: 5

The name of a diode that can be used to provide a variable capacitance is:

Solution:
QUESTION: 6

Which of the statements is true for p-type semiconductors?

Solution:

In a p-type semiconductor, the holes are the majority carriers, while the electrons are the minority carriers. A p-type semiconductor is obtained when trivalent atoms, such as aluminium, are doped in silicon atoms.

QUESTION: 7

In an unbiased p-n junction, holes diffuse from the p-region to n-region because

Solution:
QUESTION: 8

Why does current flow in the forward-bias direction but not flow in the reverse-bias direction in a pn junction?

Solution:
QUESTION: 9

In an n- type silicondiode, which of the following statement is true :

Solution:
QUESTION: 10

P-type material is created by using a dopant from group:

Solution: