Let’s say that you are installing six lights in a building. A parallel circuit starts with a hot wire and a neutral wire which feeds the first light. The remaining five lights are connected white to white (neutral) and black to black (hot) all the way to and including the last light. Unlike the series circuit, you can remove a bulb in any of the lights and it will not cause the other lights to go out. A great example is a hallway in your house where two or more lights come on with the same switch. When one burns out, the other remains lit.
Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts
How Can I Fall Asleep?
If you’re one of those people who’s up in the middle of the night Googling sleep solutions, it might help you to learn a little about the science of sleep.
The first thing you should know if you’re having a hard time getting some shuteye, is that you’re wired to sleep regular hours...going to bed the same time each night and waking up at the same time each morning. Having a regular wake-up time seems to correlate pretty highly with the ability to fall asleep consistently. This is because it keeps you aligned with what’s known as your circadian rhythm, your body’s natural tendency to stay in sync with the cycles of day and night. And you know what controls your body’s circadian rhythm more than anything else? Light.
How Old is the Earth?
How old is Earth? Our best estimate is that the planet is 4.54 billion years old, give or take 50 million years. It’s taken scientists hundreds of years to narrow it down to that range. So the better question really is, “HOW do we know how old Earth is?”
Well, for a long time, scientists just looked for the oldest parts of the planet’s surface and then determined the age of the rocks there. The thing is, Earth is always churning around the plates that make up its surface, forming new crust and recycling older crust into the planet’s interior. So, most rocks on the surface today are an average of 100 million years old. But geologists have found older rocks, mostly those that were once in the deepest layers of the crust, but then got thrust upward before they could be recycled.
What is Love?
What is love?
It’s the kind of thing that keeps poets and philosophers up at night, but science actually has a pretty good explanation for it, too. Actually, several explanations. And the answer might change depending on what kind of scientist you ask. A biologist would say it’s all about reproduction, and the evolution and survival of a species. A psychologist may go on about our need for togetherness and acceptance. But possibly the best way to understand love is through chemistry. Brain chemistry.
Why is the Sky Blue?
Click for the Filipino/Tagalog version of this article, Bakit Kulay Asul Ang Langit?
Why is the sky blue?
The sky is blue because of three things:
1. Light from the sun
2. Particles in our atmosphere
3. The fact that you’re human.
Let’s start with how sunlight interacts with particles in the sky. I’m not talking about dust or water droplets or other big particles, which are sometimes mistakenly used to explain the sky’s blueness. Instead, it’s the very small particles in our atmosphere that make the sky look blue. I’m talking about molecules of the air itself, mostly molecular oxygen and nitrogen -- O and N . These molecules are super-abundant in our atmosphere and so small that they’re even smaller than wavelengths of visible light!
Science Periodical Test (Grade 5): Questions and Answers
These are sample questions for science periodical test (Grade V). Answers to questions are highlighted in yellow.
1. Which female reproductive organ holds the egg cells?
- A. Cervix
- B. Fallopian tube
- C. Ovary
- D. Uterus
- A. Eggs
- B. Menstruation
- C. Sperms
- D. Zygote
Subscribe to:
Posts (Atom)
