3rd Grade General Subjects Quiz: Questions And Answers

Speakers are like tiny machines that work hard to turn sounds into vibrations in the air. When you play music or someone talks into a speaker, the speaker takes the sound and turns it into fast-moving vibrations. These vibrations travel through the air like waves. When the sound waves reach our ears, they make tiny parts inside our ears move. Our brains then take all this information and understand it as something we recognize, like music, voices, or even sounds from a movie. This is how we can hear different sounds and music coming from a speaker. It's all about how the speaker creates vibrations and how our ears and brain work together to make sense of those vibrations!

The keyboard is where you type on a computer. It has all the letters, numbers, and symbols we need to write messages, play games, and tell the computer what to do. The other options, such as CPU, mouse, and monitor, are not used for typing. The CPU is the central processing unit that processes data; the mouse is used for pointing and clicking; and the monitor is the display screen. Therefore, the correct answer is keyboard.

A triangle is a shape with three sides and three corners. It can look different—some triangles have equal sides, while others have one or two longer sides. But as long as it has three sides, it’s a triangle! Triangles are commonly used in geometry to calculate angles and side lengths. They are also used in architecture and engineering to create stable structures due to their strength and stability. 

The correct answer is "I was sitting on my chair." This sentence is correct because it uses the past tense of the verb "to be" (was) and the action word "sitting," which shows something was happening in the past. When we want to talk about something that was happening before, we use "was" or "were" and add "ing" to the verb.

The correct answer is "I played football." This sentence uses the past tense verb "played" to indicate that the action of playing football occurred in the past. The other options either use present tense verbs ("I play football" and "I am playing football") or have incorrect sentence structure ("I playing football").

Washington, D.C. is the capital of the United States. It is where the president lives in the White House and where the government makes important decisions. It’s not in any state but is in a special area called the District of Columbia.

Let's break it down step-by-step!

1. Start with your marbles: You begin with 530 marbles. That's a lot of marbles!


2. Oops, you lost some! You lose 100 marbles. So now you have 430 marbles left (530 - 100 = 430).


3. Wow, you found more! You're lucky! You find 400 more marbles. Now you have 830 marbles (430 + 400 = 830).


4. Oh no, you lost some again! You lose another 100 marbles. That means you have 730 marbles left (830 - 100 = 730).

So, even though you lost some marbles along the way, you still have a lot left – 730 marbles!

It is true that the sun is a star and that it is the closest star to Earth. It provides us with light and heat, which makes life on Earth possible. Photosynthesis, the process by which plants transform sunlight into energy, depends on the sun. Earth wouldn't be able to support life if it weren't for the Sun.

A monitor is a device that allows you to see images and pictures on the computer. It is an output device that displays the visual output from the computer's graphics card. The monitor usually consists of a screen, which can be either LCD or LED, and it is connected to the computer via a cable. The images and pictures are displayed on the monitor's screen, allowing the user to visually interact with the computer and view the content being displayed.

Jupiter is the largest planet in our solar system, both by mass and volume. It has a diameter of about 143,000 kilometers (88,846 miles), which is more than 11 times the diameter of Earth. Jupiter’s immense size allows it to hold over 1,300 Earths inside it. Composed mostly of hydrogen and helium, it's classified as a gas giant. Its strong gravity and massive magnetic field also influence many objects in the solar system, including asteroids and comets.

The present tense describes actions or states that are happening now. "I am going to school" uses the present continuous tense, which indicates an action happening at the moment of speaking. In order to describe an action that was completed in the past and is relevant to the present, Option A uses the future tense ("will go"), Option B uses the past tense ("went"), and Option D uses the present perfect tense ("have gone").

When you multiply 5 and 6, it means you are adding the number 5 six times. Let’s break it into steps:

1. Start with 5.


2. Add 5 again: 5 + 5 = 10.


3. Add 5 more: 10 + 5 = 15.


4. Add another 5: 15 + 5 = 20.


5. Add 5 again: 20 + 5 = 25.


6. Add the last 5: 25 + 5 = 30.

So, when you add 5 six times, the total is 30. Multiplication is just a faster way to do this. Instead of adding over and over, you can multiply 5 × 6, and the answer is 30!

Evaporation happens when the Sun heats water, turning it into vapor or gas. For example, when puddles disappear after a sunny day, that's evaporation! This process is part of the water cycle, which helps move water around the Earth. Evaporation is essential for the Earth's ecosystems as it allows water to be recycled and redistributed. Without evaporation, many regions would not receive the necessary rainfall for plant growth and other vital processes.

Living things need sunlight, food, and water to survive. Sunlight helps plants make their food through photosynthesis, which gives them energy. Food provides all living things with the nutrients and energy they need to grow and live. Water is important for many body functions, like keeping the temperature right and moving nutrients and waste. Plastic is not needed for survival and does not give any nutrients or energy to living things.