Explanation

Fossil fuels like coal, oil, and natural gas are primarily composed of carbon and hydrogen.

These elements are stored energy from ancient plants and organisms.

When burned, they release energy along with carbon dioxide and water.

The high carbon and hydrogen content makes them excellent sources of fuel.

Oxygen and nitrogen are present in very small amounts compared to carbon and hydrogen.

Explanation

LPG (Liquefied Petroleum Gas)

Mainly consists of hydrocarbons like propane and butane.

These are gases composed of hydrogen and carbon atoms.

It is used as fuel for cooking and heating.

Explanation

Air always moves from regions of high pressure to low pressure.

This movement creates wind and drives weather patterns.

The greater the pressure difference, the stronger the wind.

High-pressure areas are usually associated with clear skies.

Low-pressure areas often bring clouds and precipitation.

Explanation

A comet moves fastest when it is closest to the Sun, called perihelion.

The Sun’s gravity pulls the comet strongly, increasing its speed.

At aphelion (farthest point from the Sun), its speed is much slower.

This follows Kepler’s laws of planetary motion.

The increase in speed also causes the comet’s tail to become more visible.

Explanation

The Sun produces energy through nuclear fusion in its core.

In fusion, hydrogen nuclei combine to form helium, releasing huge energy.

This energy radiates as sunlight, heat, and solar radiation.

Fusion is different from fission, which splits heavy nuclei.

Solar energy powers life on Earth and can be harnessed for electricity.

Explanation

The Shandur Polo Festival is usually held every year from July 7 to July 9. 

It is a sports festival heldat the Shandur Polo Ground in Pakistan

Located at the boundary of the Gupis-Yasin and Chitral Districts.

Played between the teams of Gilgit Baltistan and Chitral, 

Established 1930

Founder: Colonel Evelyn Hey Cobb

Explanation

Given:

$$X : Y = 3 : 4 quad text{and} quad Y : Z = 5 : 8$$

Step 1: Make Y common

• From $X:Y=3:4$, let$X=3k$, $Y = 4k$

• From $Y:Z = 5:8$, let $Y = 5m$, $Z=8m$

Step 2: Equate Y

$$4k = 5m implies k = frac{5}{4} m$$

Then:

$$X = 3k = 3 cdot frac{5}{4} m = frac{15}{4} m$$ $$Y = 4k = 5m$$$$Z = 8m$$

Step 3: Compute the expression

$$frac{2Y}{3X - Y + 2Z} = frac{2 cdot 5m}{3 cdot frac{15}{4} m - 5m + 2 cdot 8 m}$$3X−Y+2Z​=2⋅5m/ 3⋅15​/4m−5m+2⋅8m​

Numerator: $2\cdot 5m=10m$

Denominator:

3⋅15/4​m=45​/4m
45/4​m−5m+16m=45/4​m−20​/4m+64/4​m=89/4​m$$frac{2Y}{3X - Y + 2Z} = frac{10 m}{frac{89}{4} m} = frac{10 cdot 4}{89} = frac{40}{89}$$3X−Y+2Z​=10m​/89/4=10⋅4/89​=40/89​

Explanation

Submandible refers to the area under the lower jaw (mandible).

It is close to the ear region.

It contains submandibular glands, which are salivary glands.

Explanation

Perihelion is the point in a comet’s orbit closest to the Sun.

According to Kepler’s Second Law, a comet moves faster when closer to the Sun.

Aphelion is the farthest point from the Sun, where speed is minimum.

The increase in speed is due to Sun’s gravitational pull.

This principle applies to all celestial bodies in elliptical orbits.

Explanation

A cell is the basic structural and functional unit of life.

All plant and animal tissues are made up of cells.

Nitrogen, phosphorus, and oxygen are elements, not units of tissue.