Yes, pumpkin does cook faster when the lid is on the saucepan. The reason for this is that the lid traps the steam inside the pan which speeds the cooking process.
To cook spaghetti, bring a saucepan of salt water to the boil. Place the spaghetti in the saucepan and cover with a tight fitting lid. Cook for about 15-20 minutes. Drain the pasta and serve with your favorite sauce.
It is best to cook soup very slowly, so always avoid fast boil. You can use a lid, but have it slightly lifted.
keep the lid off they will cook faster mate
Depending on the type of metal your pan is made of, it usually expands when hot, putting a cold lid on it sometimes it will not fit.
One reason to use a covered pan is so there is not any splatter. Using a lid on a pan also helps the food cook faster.
saucepan and its lid
Faster without a lid because the lid recaptures steam and condenses it back
A glass of water evaporate faster without a lid.
The liquid in the pan gets hot, and creates water vapor. The lid, blanketed by the outside air, is cooler than the liquid in the pan, so the water condenses on the underside of the lid.
Putting a lid on the pan makes the water boil quicker because the heat is trapped, less is escaping, so the water's temperature has more time to increase, so it gets more hot and boils faster.
Less heat will escape with the lid on. As the pressure inside the pan increases, the liquid boils faster - so both aspects combined makes the water to boil faster and save energy. Without a lid, the water won't boil as fast or as quickly, and more energy will be used.
Water will boil faster with the pan lid on. Keeping the pan lid on traps some of the heat and steam in the pan which would otherwise escape, thereby increasing the temperature, and bringing the water to a boil more quickly. To keep a full pot from boiling over, be sure and keep the side of the lid farthest from you cracked just slightly, so a little of the steam can escape.