In first case, eyes of student are in level of the thermometer, so it is correct way to measure temperature using clinical thermometer

(a) All indicators do not change colour with acids as well as bases, e.g. turmeric changes its colour to pink with the base but it remains yellow with acid.
Therefore, statement (i) is incorrect. There are some indicators which change colour with both acid and base, e.g. methyl orange, litmus, thus statement (ii) and (iii) are also incorrect. Statement (iv) is the correct conclusion about indicators.

The handles of most utensils are made of plastic and wood because plastic and wood are poor conductors of heat. We can easily hold the handle with bare hands even if the utensils are hot. This helps us to remove hot utensils from the flame.

There are following two reasons of excessive currents in our houses:
(i) Direct touching of wires : This may happen if the insulation on the wires has come off due to wear and tear. This may cause a short circuit.
(ii) Connection of many devices to a single socket. This may overload in the circuit

A long tube along the neck and the chest is called a food pipe or oesophagus. The swallowed food passes into the food pipe. Food is pushed down by the movement of the wall of the food pipe. It pushed the food towards stomach.

Two commonly used bases in the laboratory are ammonium hydroxide (NH₄OH) and sodium hydroxide (NaOH)

Some organisms live together and share shelter and nutrients, Such relationship is called symbiotic relationship.
Example: Lichens

Radiation is the mode of transfer of heat in which medium is not required.

(a) Litmus (blue litmus paper)
(b) Turmeric

The citric acid in lemon juice and oxalic acid in tomato.

Take a rectangular box with a glass front. Make a small window on one of its sides and a hole on the top. Fix a paper pipe into the hole of the top to form a chimney. Now keep a candle in the box below the chimney. Keep your hand above the chimney. It will be observed that hot air is coming out of chimney. Now put a lighted incense stick near the window. Soon you will notice that incense smoke comes out of the window. This happens due to the convection current set up inside the box.

The air near the heat source gets hot and rises. The cold air from sides takes its place. In this way, air gets heated. This gives interesting phenomenon in coastal regions.
(i) During the day, land gets heated faster than water. The air over the land becomes hotter and rises up. The cooler air from sea rushes in towards the land to take its place. The warm air from land moves towards sea to complete the cycle. The air from sea is cool and is called sea breeze.
(ii) At night, it is exactly the reverse. The water cools down more slowly than land. So, the cool air from land moves towards sea. This is called land breeze.

Electric heater and ironwork on the basis of heating effect of electricity. When an electric current passes through the wires they become hot. Electric heater or iron contains a coil of wire. This coil of wire is called an element. When these appliances are switched on after connecting to the electric supply, their elements become red hot and give out heat.

Carbohydrates are complex substances. These complex substances cannot be utilised as such as we eat. They are broken down into simpler substances like glucose. This process is called digestion of carbohydrates.

(i) It helps in talking.
(ii) It helps to mix saliva with the food.
(iii)It also helps in swallowing food.

Add a drop of phenolphthalein separately in liquids A, B and C. The one which turns pink is sodium hydroxide, let it be A. Divide this into two parts. Now add a few drops of other solutions in the above solution taken into parts. The solution which again turns solution A colourless is hydrochloric acid. Let it be B. Then solution left is sugar.

As a fact that warm air is much lighter than the cold air, so being heavier the cold air from air conditioner moves downwards while the hot air moves upwards at the lower level and gets cooled and come downwards once again. So, due to this convection of heat are set in the air and room gets warmer faster.

Nepenthes or pitcher plant modifies its leaf axis into a long tubular pitcher to form a pitfall trap. Inside the pitcher sticky liquid is present. When any insect comes in contact with the leaf, the lid present on it is closed and insect is trapped. The liquid contains digestive enzymes which slowly digest the trapped insects.

The swallowed food moves downwards in the alimentary canal because of the alternate relaxation contraction movement of muscles in the wall of foodpipe called peristalsis.

When the ingest food in our mouth, salivary glands of the mouth secrete saliva which moistens the food. It also converts the starch into sugar. The tongue helps in chewing by moving the food in various directions. Saliva contains enzyme called salivary amylase which converts starch into sugar.

From mouth, food goes into food pipe called oesophagus. As food enters into the food pipe, muscles of its wall starts contraction and relaxation movement. This movement is called peristaltic movement that pushes the food into the stomach. The peristaltic movement occurs throughout the alimentary canal. The oesophagus leads the food to a saclike structure called stomach. The food is churned and partly digested in the stomach. The semi-solid food passes from the stomach to much coiled tube-like structure called the small intestine. The small intestine serves two purposes-digestion and absorption of the digested food. It is about 20 feet long. The inner surface of the small intestine has a large number of finger-like projections called villi. The villi increase the surface area for the absorption of digested food. The absorbed food enters into the blood stream and carried away to various parts of the body for assimilation. The undigested food moves from the small intestine to the large intestine where mainly absorption of water from the undigestion takes place. From the large intestine, the undigested food passes to the rectum which pushes it out of the body through the opening called the anus as faeces.

(b) Carbohydrates and oxygen.
(c) Liberated-oxygen, Utilised-carbon dioxide.
(d) All plants cannot do photosynthesis, only green plants can do photosynthesis.

(a) No, the amount of heat produced in both the wires will be different because amount of heat produced in a wire on passing electric current depends on the length of wire and here length is different for both the wires.
(b) No, the amount of heat produced in the wire of same length but different thickness cannot be same because amount of heat produced in a wire also depends on the thickness of the wire.