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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Consider the following statements about ‘Human Body’:
1. Muscles contain special proteins which contract and relax to cause movement.
2. We can control the movement of all the muscles in our body.
Which of the statement(s) given above is/are correct?
With reference to the uses of ‘concave mirrors’, read the following statements carefully:
1. They are commonly used in vehicles headlights to get powerful parallel beams of light.
2. They are often used as shaving mirrors to see a larger image of the face.
3. They are fitted on the sides of the vehicle to have a wider field of view.
4. Large concave mirrors are used to concentrate sunlight to produce heat in solar furnaces.
Which of the statements given above is/are correct?
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:
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 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?
In the context of ‘immunity’ in human body, which of the following statements is/are correct?
1. Skin on our body is an example of innate immunity.
2. Acquired immunity is characterised by memory.
3. Injecting the microbes deliberately during immunisation induce passive immunity.
Select the correct answer using the code given below.
Read the following statements carefully and select the correct answer from codes given below:
1. The phenomenon of splitting of white light into its seven component colours by a prism is called dispersion.
2. While passing through a prism, the violet light bends the least while the red the most.
3. Isaac Newton was the first to use a glass prism to obtain the spectrum of sunlight.
Which of the statements given above is/are correct?
Which among the following are the characteristic features of birds?
1. They are cold-blooded animals.
2. They lay eggs.
3. Two forelimbs are modified for flight.
4. They breathe through lungs.
Select the correct answer using the code given below:
Which of the following phenomena are caused due to ‘atmospheric refraction’?
1. Flickering of objects seen through a turbulent stream of hot air rising above a fire.
2. The reddening of the sun at sunrise and the sunset.
3. The apparent flattening of the Sun’s disc at sunrise and sunset.
4. The Sun is visible to us about 2 minutes before the actual sunrise, and about 2 minutes after the actual sunset.
Select the correct answer using the code given below.
In context of General Science, consider the following statements:
1. All fluids exert pressure on the base and walls of the container in which they are enclosed.
2. All objects experience a downward force of buoyancy when they are immersed in a fluid.
3. The magnitude of buoyancy force is independent of the density of the fluid in which the object is immersed.
Which of the statement(s) given above is/are correct?