Does using lighting to grow plants indoors affect the vitamins/minerals/overall health of the plants? -
It is not so much the indoor lights that affect the way plants use nutrients, but rather the light spectrum in the indoor lights. Sunlight contains both a warm and cool spectrum, which is ideal for plants. Typical indoors lights tend to be either warm spectrum or cool spectrum, which means that the full range is not available to indoor plants. A "grow" light will typically have both spectrum.
This article has more information:
North/South or East/West. I have 2 contridicting sources - now I'm confused.
The reason you get conflicting info is because they both have their advantages. North/south is best for if you will be growing mainly in the summer as you will get a bit more sunlight. East/west is better for growing crops in the spring and fall, as it can help keep away frost a bit.
Either way, the advantages to planting orientation are only slight. You are best off planting in a way that is convenient for you.
Do streetlights affect plant growth in a vegetable garden?
They should not affect their growth.
What will happen to a plant when grown in complete darkness?
When you grow asparagus this way they are white.
I would like to know about the proper light which is useful for apartment plants to help them to grow more. I need to know what kind of artificial lighting might be useful in this regard (i. e. langston, fluorescent, etc).
Florescent light is sufficient to supplement in an apartment. It will need to be placed within a few inches of the plant though to give enough light. LEDs can also be used.
Please give me details about light requirement for different vegetables. Also, for flowers, cereals, pulses, etc.
Most vegetables need at least 5 hours of sunlight. There are very few vegetables that can take less than that. This goes for cereal plants and herbs as well.
As for flowers, there are so many that I could not possibly list them all here. Most places that sell the flowers have the light requirements listed on the plant or you can search for the name of the plant with the words light requirements and find them.
I was hoping to start an indoor garden this winter. Turns out I already have a fluorescent light lying around the house, the 18 inch type, 15W warm white. Would that be sufficient wattage or should I get a new light?
That should be strong enough, but depending on the type of plants you plan on growing, the bulbs may need to be closer to the plants. Low light plants do not need to be as close, and high light plants would need the lights very close. Here is an article to help: https://www.gardeningknowhow.com/houseplants/hpgen/fluorescent-lighting-for-indoor-gardening.htm