Which diagram shows image formation of an object on a screen by a converging lens?

Examples of responses to hormones are listed.
1. Growth of facial hair.
2. Increased blood pressure and pulse rate.
3. Widened pupils.
Which responses are caused by the hormone adrenaline?

An object of height 8 cm ls placed at a distance of 40 cm In front of a convex lens of focal length 20 cm. The size of image is _______.

If 10 mL of H₂SO₄ is mixed with 10 mL of Mg(OH)₂ of the same concentration, the resultant solution will give the following colour with universal indicator.

what is the nature of ozone?

Which of the following is proper sequence of trophic levels?

A student of class 10, is not able to see clearly the black board question when seated at a distance of 5 m from the board, the defect he is suffering from is

Cytokinins are mostly present is:

Which of the following salts has no water of crystallization?

Freezing of water is a

Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

Which one of the following is an artificial ecosystem?

Green dots present on a leaf are cell organelles called

The filtration units of kidneys are called

In the reaction, SO₂(g) + 2H₂S(g) \(\rightarrow\) 2H₂O(l) + S(s), the reducing agent is

State the function of each of the following parts of the human eye :
(i) Cornea
(ii) Iris
(iii) Pupil
(iv) Retina
(b) Millions of people of the developing countries are suffering from corneal blindness. This disease can be cured by replacing the defective cornea with the cornea of a donated eye. Your school has organised a campaign in the school and its neighbourhood in order to create awareness about this fact and motivate people to donate their eyes after death. How can you along with your classmates contribute in this noble cause? State the objectives of organising such campaigns.

Write the chemical formula of washing soda and baking soda. Which one of these two is an ingredient of antacids? How does it provide relief in stomach ache?

Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?

Define a lens

What is the insoluble substance formed in a chemical reaction called?

When and where do we see a rainbow? How is a rainbow formed? Draw a labelled diagram to illustrate the formation of a rainbow

What is lymph?

Why is the use of iodised salt advisable?

Manju has two convex lenses P and Q made of the same material as shown in the figure.
She is looking at printed text on a page using lens P. She notices that when she slowly takes the lens away from the page, the text turns upside down when the lens crosses a distance of 10 cm from the page.
(i) Which characteristic of lens P does the distance 10 cm signify?
(ii) If Manju does the same with lens Q, at what distance will the inversion of the image happen-less than, equal to or more than 10 cm? Justify your answer.

Select the ones that belongs to the first trophic level?
Grasshopper, rose plant, cockroach, vulture, neem plant

FeSO₄.7H₂O, green colour crystals on heating, changes colour. Why?

State the difference between rods and cones cells in the retina of human eye. Draw a neat diagram of human eye.

A student wanted to find out if starch was present in both leaves grown in direct sunlight and leaves grown in the shade. Plan an investigation to determine if starch is present in both types of leaf.

What is meant by the water of crystallization? How many molecules of water are present in hydrated copper sulphate? Write its formula. What colour change do you observe when it is heated?

Assertion: Pancreatic juice digests starch, proteins and fats.
Reason: Pancreatic juice contains digestive enzymes like pancreatic amylase, trypsin and lipase.
Codes
(a) Both A and R are true and R is correct explanation of the assertion.
(b) Both A and R are true but R is not the correct explanation of the assertion.
(c) A is true but R is false.
(d) A is false but R is true.

Assertion: Paper cups are better option than plastic cups for serving tea. Reason: Paper cups are biodegradable and can even be disposed of by burning.
Reason: Paper cups are biodegradable and can even be disposed of by burning.
Codes
(a) Both A and R are true and R is correct explanation of the assertion.
(b) Both A and R are true but R is not the correct explanation of the assertion.
(c) A is true but R is false.
(d) A is false but R is true

Assertion: Salt of KNO₃ is formed by strong base and weak acid.
Reason: Salt of NH₄CI is formed by weak base and strong acid.
Codes
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.

Assertion: Gustatory receptor detect taste while olfactory receptors detect smell.
Reason: Receptors helps in detecting the environment, they are present on the nerve cells.
Codes
(a) If both assertion and reason are true and the reason is correct explanation of assertion.
(b) If both assertion and reason are true but reason is not a correct explanation of assertion.
(c) If assertion is true and reason is false.
(d) If both assertion and reason are false.

Assertion: Ferrous sulphate crystals (FeSO₄•7H₂O) lose water when heated.
Reason: The colour of the crystals changes and it is a decomposition reaction.
Codes
(a) If both assertion and reason are true and the reason is correct explanation of assertion.
(b) If both assertion and reason are true but reason is not a correct explanation of assertion.
(c) If assertion is true and reason is false.
(d) If both assertion and reason are false.

The curve shows the amount of emission of chemicals in the air that depletes ozone layer from the year 1961 to 2014.

Answer the following questions based on the above information
(a) Where do we use the chemicals that would release the harmful chemicals in the air?
(b) Why the emission of harmful gases was less in 1960's and 2010 onwards?
(c) In which year was the ozone depletion maximum?
(i) 1970-1972 (ii) 1979-1980 (iii) 1988-1990 (iv) 1998-2000
(d) Chemical that depletes ozone layer is
(i) CFC (ii) CNC (iii) CMC (iv) CLC

Answer the following questions based on the above information
(a) Refer to Table B showing the blood pressure of male and female. Infer the disease which can be diagnosed in a boy of 14 years who have same blood pressure as a 60 year old man.
(b) Identify the hormone whose level in the blood is responsible for raise in blood pressure in certain situations.
(c) Which of the following trend in blood pressure range is seen with advancement of age from teenage to old age?
(i) Increase
(ii) Remains same
(iii) Decrease
(iv) Fluctuates
(d) Which of the following is incorrect in case of high blood pressure?
(i) Increased resistance to blood flow
(ii) Decreased resistance to blood flow
(iii) Rupture of an artery
(iv) Internal bleeding

To demonstrate the transpiration from the leaf surface, Saily took four banyan leaves. Both the surfaces of the A leaf, lower surface (with stomata) of Bleaf, upper surface (without stomata) of C leaf are vaselined. The Vaseline is not applied on the D leaf. Now, as shown in the figure the leaves are hanged so that they may transpire freely.

Comparison of transpiration. Demonstration by four leave

Answer the following questions based on the above information
(a) Was the Vaseline effective in prevention of water loss?
(b) Which surface allowed more loss of water?
(c) Percentage loss of mass in leaf C is-
(i) 38.5 (ii) 37.5 (iii) 36.5 (iv) 39.5
(d) The maximum loss of mass take place in leaf
(i) A (ii) B (iii) C (iv) D

Answer the following questions based on the above information
(a) Why is the pH of NH₄ Cl less than 7?
(b) What is the nature of ammonium sulphate solution?
(c) NaHCO₃ gives brisk-effervescence when reacts with
(i) HCl     (ii) NH₄OH    (iii) NaOH     (iv) K₂CO₃
(d) Which species formed on heating NaHCO₃ is used to make bread and cakes fluffy, soft and spongy?
(i) Na₂CO₃    (ii) CO₂     (iii) H₂O       (iv) H₂CO₃

The reaction between MnO₂ with HCI is depicted in the following diagram. It was observed that a gas with bleaching abilities was released.

(i) ldentify the type of chemical reaction between MnO₂ and HCI.
(ii) Which reagent does chlorine gas reacts with to form bleaching powder?
(iii) Write the balanced chemical reaction of part (i) and identify the oxidised and reduced species.
Or
(iii) (a) In the above discussed reaction, what is the nature of MnO₂?
(b) What will happen, if we take dry HCI gas instead of aqueous solution of HCI?

Mathematics teacher of a school took her 10th standard students to show Red fort. It was a part of their Educational trip. The teacher had interest in history as well. She narrated the facts of Red fort to students. Then the teacher said in this monument one can find combination of solid figures. There are 2 pillars which are cylindrical in shape. Also 2 domes at the corners which are hemispherical.7 smaller domes at the centre. Flag hoisting ceremony on Independence Day takes place near these domes.

(i) How much cloth material will be required to cover 2 big domes each of radius 2.5 metres? (Take π = 22/7)

(ii) Write the formula to find the volume of a cylindrical pillar :

(iii) Find the lateral surface area of two pillars if height of the pillar is 7 m and radius of the base is 1.4m.

(iv) How much is the volume of a hemisphere if the radius of the base is 3.5 m?

(v) What is the ratio of sum of volumes of two hemispheres of radius 1 cm each to the volume of a sphere of radius 2 cm?

Each capillary cluster in the kidney is associated with the cup- shaped end of a tube that collects the filtered urine (see adjoining figure). Each kidney has large numbers of these filtration units called nephrons packed close together. Some substances in the initial filtrate, such as glucose, amino acids, salts and a major amount of water, are selectively re-absorbed as the urine flows along the tube. The amount of water reabsorbed depends on how much excess water there is in the body, and on how much of dissolved waste there is to be excreted. The urine forming in each kidney eventually enters a long tube, the ureter, which connects the kidneys with the urinary bladder. Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra. The bladder is muscular, so it is under nervous control, as we have discussed elsewhere. As a result, we can usually control the urge to urinate.

(i) Which of the following is the correct path taken by urine in our body ?
(a) kidney → ureter → urethra → bladder
(b) kidney → bladder → urethra → ureter
(c) kidney → ureter → bladder → urethra
(d) bladder → kidney → ureter → urethra
(ii) The excretory unit in the human excretory system is called :

(iii) The substance which is not reabsorbed into the blood capillaries surrounding the tubule of a nephron is mainly 

(iv) The procedure of cleaning the blood of a person by using a kidney machine is known as :

(v) The kidneys in human beings are a part of the system for

The various steps, representing organisms in a food chain, at which the transfer of food and energy takes place are called trophic levels. Trophic levels are mainly occupied by producers and consumers. Producers belong to the first trophic level while consumers occupy various trophic levels in a food chain. Consumers are heterotrophic organisms, that are of three types - herbivores, carnivores and decomposers. A simplified version of a food chain showing various trophic levels is represented as follows.

(i) T₆ in the food chain is

(ii) If T₂ is occupied by grasshopper in a particular food chain, then T₃ and T₄ will most probably be

(iii) In an ecosystem, trophic levels are formed by

(iv) Which of the following limits the number of trophic levels in a food chain?

(v) Nitesh went to a garden. There he saw some sparrows eating worms from the green grass. After sometime suddenly an eagle attacked the bird and killed it. Which one among these organisms belong to trophic level 2 and 3 respectively in the food chain operating there?