Consider the following statements about ‘Biochemical Oxygen Demand’ (BOD):
1. It is the amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water.
2. Highly polluted water have BOD value of less than 5 ppm.
Which of the statements given above is/are correct?
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A lemon kept in water in a glass tumbler appears to be bigger than its actual size, when viewed from the sides. This is because of which of the following reasons:
Fertilizers are commercially produced plant nutrients. In this context, consider the following statements:
1. Fertilizers get washed away due to excessive irrigation.
2. Micro-organisms in the soil are harmed by the continuous use of fertilizers.
3. Fertilizers supply nitrogen, phosphorus and sodium to the soil.
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.
The presence of certain minerals is essential in water, however, if found in excess they can be harmful to our body. In this context, which of the following statements are correct?
1. Deficiency of fluoride in drinking water causes diseases such as tooth decay.
2. Excessive sulphate in drinking water causes laxative effect.
3. Excess lead in drinking water can cause disease such as ‘blue baby’ syndrome.
Select the correct answer using the code given below.
Consider the following statements:
1. A person with myopia can see nearby objects clearly but cannot see distant objects distinctly.
2. In a myopic eye, the image of a distant object is formed behind the retina and not at the retina itself.
3. The defect of myopia can be corrected by using a concave lens of suitable power.
Which of the statements given above is/are correct?
If an opaque object on the path of light becomes very small, light has a tendency to bend around it and not walk in a straight line. This effect is known as:
Consider the following statements about the ‘fuel obtained from plastic waste’:
1. It has low octane rating.
2. Lead content is absent in it.
3. It is known as green fuel.
Which of the statements given above is/are correct?
Consider the following statements about ‘Biochemical Oxygen Demand’ (BOD):
1. It is the amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water.
2. Highly polluted water have BOD value of less than 5 ppm.
Which of the statements 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?
The immune system is a complex network of cells known as immune cells that contains lymphocytes. In this context, consider the following statements:
1. Lymphocytes are red blood cells and one of the body's main types of immune cells.
2. Lymphocytes are made in the bone marrow and found in the blood and lymph tissue.
Which of the statements given above is/are correct?