A 'Rapid' analogy
"Why is it," my lecturer asked, pointing to a diagram of a p-n diode, "that the holes and electrons stop moving after some time?"
"Because the negative charges left behind repel the electrons?" I volunteered.
"If you were to take a Rapid from here to Tanjung Bungah", he paused for dramatic effect, "you would only reach Jelutong".
The class roared with laughter.
I must admit that I hesitated a bit to answer his subsequent questions.
Perhaps, he could have done away with that Rapid analogy.
Time is Right
Looking Back at Campus Life
4 comments:
Muahaha! Yea it always happen eh? What happened to your tagboard by the way?
What always happens? I never had a tagboard.
LOL your lecturer's funny.
Though you only stop at Jelutong, you're closer to Tanjung Bungah than you'd be if you hadn't stepped on the us at all ;-)
so why is it that they stop moving?
so why is it that they stop moving?
Refer to the diagram in the post.
Region P is crowded with positively-charged holes, which migrate across to N.
In the same way, region N is crowded with negatively-charged electrons; they migrate over to P.
As holes migrate over, they leave negative ions at P. Electrons migrating over leave positive ions behind at N.
These leftover positive and negative ions form an electric field. Over time, this electric field becomes very strong and stops both sides from migrating.
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