Questions

Strength of concrete increases with increase in water cement ratio as the strength of the cement is directly proportional to water cement ratio.

From the given circuit,

The resistors R1 and R2 are in parallel connection and R3 is in series with R1 & R2

The equivalent resistance of R1 and R2 is

Req = (12 × 4)/(12 + 4) = 3 Ω.

Adding R3 in series with the pair gives

R = Req + 9

R = 3 + 9

R = 12 Ω.

The lightest computer is the tablet.

Labyrinth which is part of the ear is the main organ of balance in the human body.

An eclipse happens when a planet or a moon gets in the way of the sun's light. Our planet Earth experiances two types of eclipses. They are Solar and Lunar eclipses.

Solar Eclipse : This occurs when The Sun, the Moon and the Earth are in a straight line. The moon being in middle blocks sun rays falling on the Earth.

Lunar Eclipse : The Sun, the Earth and the Moon are in a straight line. The Earth being in middle and moon in the shadow of Earth behind it.

Cotton Gin was invented by Eli Whitney in 1793, which is used to separate cotton seeds from cotton fiber.

Hence, it was an important invention because it dramatically reduced the amount of time it took to separate cotton seeds from cotton fiber.

 I have used following 4 types of Methodologies: 

1. Boundary value analysis   

2. Equivalence partitioning   

3. Error guessing   

4. Cause effect graphing