Combustion and Flame

Water is used to extinguish fire because it

• raises the ignition temperature of a burning substance

• lowers the ignition temperature of the burning substance

• cools the burning substance to a temperature below its ignition temperature

• conducts heat

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A fuel gives yellow flame due to

• incomplete combustion

• complete combustion

• spontaneous combustion

• rapid combustion

The black residue left behind during incomplete combustion is

• ash

• soot

• wax

• fuel

The temperature of the middle zone of the candle flame is about

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The hottest part of a candle flame is the

• blue zone

• invisible zone

• visible zone

• dark inner zone

Read the statements and select the correct option.

Statement 1: Kerosene oil and wood do not catch fire on their own at room temperature.

Statement 2: A combustible material cannot catch fire as long as its temperature is lower than the ignition temperature.

• Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.

• Both statements 1 and 2 are true and statement 2 is not the correct explanation of statement 1.

• Statement 1 is true and statement 2 is false

• Both statements 1 and 2 are false

Tags

NGSS.MS-PS1-2

Which of the following statements are true?

1. Yellow flames are ideal for heating

2. The substances which vaporise during burning gives flames

3. Luminous zone contains unburnt carbon particles

4. The non-luminous zone has the highest temperature

• 1, 2 and 3

• 1, 2 and 4

• 2, 3 and 4

• 1, 3 and 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Match column 1 and column 2 and select the correct option from the given codes.

Column 1 Column2

P. Rusting i. Explosion

Q. Burning of paper ii. Spontaneous Combustion

R. Sodium iii. Rapid Combustion

S. Fire Crackers iv. Slow combustion

• P-ii, Q-iii, R-i, S-iv

• P-i, Q-iii, R-ii, S-iv

• P-iii, Q-iv, R-i, S-ii

• P-iv, Q-iii, R-ii, S-i

Tags

NGSS.HS-PS3-4

A fire can be controlled by

• lowering the ignition temperature

• cutting off the supply of supporter of combustion

• both a and b

• neither a nor b

Tags

NGSS.MS-ESS3-2

The zone of the candle flame which is moderately hot is called,

• non-luminous zone

• luminous zone

• inner dark zone

• lower blue zone