Question

Assertion: The crown fires are most destructive as they burn the treetop.
Reason: Due to crown fire the temperature of that area may rise to 700 degrees celsius.
A. If both the assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both the assertion and reason are true and the reason is not the correct explanation of the assertion.
C. If the assertion is true but the reason is false.
D. If both the assertion and reason are false.
E. If the assertion is false but the reason is true.

Answer 1

Hint: Crown fire is a type of wild forest fire that spreads from one Treetop to another treetop. The fire reaches the treetop ascending from the ground. Crown fire is also called aerial fire or canopy fire as it affects the canopy of the forest. There are suspended matter in the aerial region. Crown firing is spread by the burning of this suspended matter.

Complete answer:
Crown fires are very destructive as they can destroy a large area of vegetation and aerial fuel in the forest. They spread very fastly from one treetop to another treetop burning the suspended matter in the air. When a crown fire is being ignited it is called crowning.
Crowning depends on many factors like the height of the canopy, the distance between the trees, the density of the forest, the moisture content in the atmosphere. Crown fire is a vastly spreading fire. In a highly dense forest as the number of trees is more the moisture content and humidity will also be high, loving the chance of crown fire. In less dense forest areas the humidity will be high that facilitates fire. The dry leaves and vegetation catch fire fastly. Leaves and grasses have a low density as they contain only a little amount of water and can ignite easily.
The temperature of the area may rise to 700 degrees Celsius or more which increases the impact of the destruction. The high temperature spreads faster to the area, even before the fire reaches. This increase in temperature causes the preheating, warming up the combustible materials in the area, speeding up the ignition.
The correct answer is option (A) If both the assertion and reason are true and the reason is the correct explanation of the assertion.

Note:
The spread of wildfires can be in four levels. They are ground fire, surface fire, ladder fire, and crown fire. In-ground fire, burning of roots and organic matter takes place. In surface or crawling fire, grasses and low lying vegetation on the surface get ignited. In ladder fire, ignition of small trees, between the surface and canopy occurs. In a crown fire, the canopy of the forest gets ignited.