When CNG or LPG undergoes complete combustion, the products forme

Subject

Science

Class

TET Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

1.

Given below are a few chemical processes
A. Rusting of iron
B. Burning of a candle
C. Respiration
D. Photosynthesis'

Which two of these represent slow combustion? 

  • D and A

  • A and C

  • B and C

  • B and D


2.

The smallest of living organisms with cell wall are

  • yeast

  • cyanobacteria

  • algae

  • bacteria


Advertisement

3.

When CNG or LPG undergoes complete combustion, the products formed are

  • CO2 and H2O

  • CO2, SO2, and H2O

  • CO2 only

  • CO2, CO, and H2O


A.

CO2 and H2O

CNG (Compressed Natural Gas) mainly contains methane (CH4) and LPG (Liquefied Petroleum Gas) contains butane (C4H10) and propane (CH3H8). Complete combustion of a hydrocarbon (CH4, C2H3, C3H8, C4H10) produces CO2 and H2O.

CH+ 2OCO+ 2H2O
C3H+ 5O3CO2 + 4H2O
C4H10 132O25CO2+5H2O

Hence, the products of complete combustion of CNG and LPG are mainly CO2 and H2O.


Advertisement
4.

Assessment in Science should focus more on testing the ability of students to

  • answer open-ended questions

  • be sufficiently equipped for higher learning

  • state the facts and principles of Science correctly

  • apply the understanding of concepts to unfamiliar situations in everyday life


Advertisement
5.

The SI unit of calorific value is

  • J/kg

  • Kilocalorie/kg

  • kJ/kg

  • Calorie


6.

The process of converting sugars into alcohols is known as

  • pasteurisation

  • sterilisation

  • homogenisation

  • fermentation


7.

One of the main limitations of the Project method of teaching Science is that

  • knowledge is not acquired in a sequential manner

  • integration of concept in various subjects can be achieved

  • the students have to perform excessive mental and physical work

  • it is a psychological method


8.

Summative Assessment in Science should mainly focus on 

  • assessing observation skills

  • diagnosing the areas of learning difficulties of students

  • testing of mainly the practical skills

  • testing important theoretical concepts


Advertisement
9.

The dietary fibres are

  • made up of collagen fibres

  • made up of proteins

  • also called roughage

  • made up of cellulose and proteins


10.

If the frequency of vibrations of a body is decreased and its amplitude is increased, then

  • pitch increases but loudness decreases

  • pitch decreases but loudness increases

  • both pitch and loudness of sound produced will increase.

  • both pitch and loudness of sound produced will decrease


Advertisement