Some countries now use alcohol as an additive in petrol. In context of this, consider the following statements:
1. Addition of alcohol increases the burning efficiency of petrol and reduces knocking.
2. Petrol added with small quantities of alcohol becomes more stable and doesn’t become too hot in warm areas or too cold in freezing temperatures.
3. Alcohol is a cleaner fuel which gives rise to only carbon dioxide and water on burning in sufficient oxygen.
Which of the statements given above is the correct reason for using alcohol as an additive in petrol?
More Questions Selected Just For You. Attempt Now!
Unicellular organism are unique because they are made up of a single cell only. Which of the following is/are examples of unicellular organisms?
1. Amoeba
2. Yeast
3. Bacteria
Select the correct answer using the code given below:
The parasitic nutritive strategy, by which some organisms derive nutrition from plants or animals without killing them, is used by which of the following organisms?
1. Cuscuta (amar-bel)
2. Ticks
3. Bread moulds
4. Tape-worms
Select the correct answer using the code given below.
Which of the following are the properties of the image formed by a plane mirror?
1. The image is always real and erect.
2. The size of the image is equal to that of the object.
3. The image formed is as far behind the mirror as the object is in front of it.
4. The image is laterally inverted.
Select the correct answer using the code given below.
Consider the following statements about the ‘scattering of light’:
1. Very fine particles scatter mainly blue light while particles of larger size scatter light of longer wavelengths.
2. If the size of the scattering particles is large enough, then, the scattered light may even appear white.
Which of the statements given above is/are correct?
Consider the following statements:
1. The direction of current is taken opposite to the direction of flow of electrons.
2. Resistance is a property of a conductor that generates heat in the electrical circuit.
3. The SI unit of electric current is Amperes.
Select the correct answer using the code given below:
In context of cells in the human body, consider the following statements:
1. The shape and size of cells are related to the specific function they perform.
2. A cell is able to live and perform all its functions because of its components known as organelles.
3. All cells present in human body have the same organelles.
Select the correct answer using the code given below:
The twinkling of a star occurs due to atmospheric refraction of starlight. This twinkling phenomenon occurs only in stars and not in planets, it is because of which of the following reasons?
Water vapour present in the atmosphere is formed due to which of the following factors?
1. Heating of water bodies.
2. Activities of living organisms.
3. Weathering of rocks.
4. Photosynthesis.
Select the correct answer using the code given below:
Compass is an important tool used for navigation since old days. In this context, consider the following statements:
1. The compass needle is a magnet which align itself in a particular direction.
2. The compass needle always points towards the magnetic south pole of the earth.
Which of the statement(s) given above is/are correct?
Consider the following statements with reference to the ‘magnetic field’ of a bar magnet:
1. Magnetic field is a quantity that has both direction and magnitude.
2. Inside the magnet, the direction of field lines is from its south pole to north pole.
3. Magnetic field-lines of two different magnets can intersect each other.
Which of the statement(s) given above is/are correct?