which graph represents what happens to the pressure in a tire as air is added to the tire, assuming the temperature is constant
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The correct option is option A.
According to the universal gas equation, the product of the pressure and volume of a gas is directly proportional to the product of the number of moles of gas and the absolute temperature of the gas.
So PV is proportional to nT.
Here, it's said that the temperature of the gas is constant. And inside a tube, the volume of the gas remains constant.
So the pressure of the gas will be directly proportional to the number of moles of gas. So as the number of moles of the gas rises, the pressure of the gas also rises. So, with addition of more gas into tyre, the pressure of gas will also increase.