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What happens to the barrier potential of a p-n junction diode under forward bias?
The context states, 'The effective barrier height under forward bias is ($V_0 – V$).' Also, 'The barrier is decreased while the barrier increases in reverse bias.'
What happens to the depletion layer width of a p-n junction diode under reverse bias?
According to the NCERT, 'As a result, the barrier height increases and the depletion region widens due to the change in the electric field' in reverse bias.
Which of the following describes the nature of current in a p-n junction diode under reverse bias?
The NCERT states, 'The electric field direction of the junction is such that if electrons on p-side or holes on n-side in their random motion come close to the junction, they will be swept to its majority zone. This drift of carriers gives rise to current. Thedrift current is of the order of a few μA.'
The p-n junction diode primarily allows the flow of current in:
The context clearly states, 'The above discussion shows that the p-n junction diode primarily allows the flow of current only in one direction (forward bias).'
What is the typical magnitude of the total diode forward current?
The NCERT states, 'The magnitude of this current is usually in mA.' (referring to forward current).
What is 'minority carrier injection' in a p-n junction diode?
The NCERT explains, 'Due to the applied voltage, electrons from n-side cross the depletion region and reach p-side (where they are minority carries). Similarly, holes from p-side cross the junction and reach the n-side (where they are minority carries). This process under forward bias is known as minority carrier injection.'
Why is the forward bias resistance of a diode low compared to its reverse bias resistance?
The NCERT text states, 'The forward bias resistance is low as compared to the reverse bias resistance.' This is because 'in forward bias... the barrier is decreased' and 'in reverse bias... the barrier increases'.
For what special cases does the current suddenly increase at very high reverse bias in a diode?
The text states, 'However, for special cases, at very high reverse bias (break down voltage), the current suddenly increases.'
Which of the following statements correctly defines the mean free path ($l$) of a gas molecule?
According to the NCERT text, 'The mean free path $l$ is the average distance covered by a molecule between two successive collisions'.
The mean free path ($l$) of gas molecules is inversely proportional to which of the following quantities, assuming other parameters remain constant?
The formula for mean free path is $l = 1 / (\sqrt{2} \pi n d^2)$. This equation clearly shows that $l$ is inversely proportional to both the number density ($n$) and the square of the diameter of the molecule ($d^2$). The NCERT text also states, 'As expected, the mean free path given by Eq. (12.40) depends inversely on the number density and the size of the molecules'.
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The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.