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# IV characteristics q watch

1. Guys pls help me out!
I don't get why the graph for a filament lamp is like this ><
Could someone tell me what is happening to the current, the voltage and the resistance here? Pls? TT

2. If I and V were directly proportional, you'd expect a straight line.

BUT, in a wire, as the current increases, the wire gets hotter which increases the resistance of the wire. So, as the voltage and hence the current are increased, the rate at which the current increases wrt voltage decreases - it can't increase as much as it did at the beginning because the resistance is now bigger - and of course in both the positive and negative directions.

Is that what you were asking or is there more....?

Hang on, I realise I've just re-explained what the text beside the diagram already explains - so I'm really not sure at all what you were asking, sorry if I'mve misunderstood.
3. I just wasn't able to grasp that text and needed someone to explain what was happening. Your explanation helped a lot, thank you so much

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