The short and long hands of a clock are 4 cm and 6 cm long respectively. Find the sum of distances travelled by their tips in 48 hours.
(a) Define excretion.
(b) Name the basic filtration unit present in the kidney.
(c) Draw excretory system in human beings and label the following organs of excretory system which perform following functions:
(i) form urine
(ii) is a long tube which collects urine from kidney
(iii) store urine until it is passed out
Draw the structural formulae of all the possible isomers of the compound with the molecular formula C3H6O and also give their electron dot structures.
A student observed a permanent slide showing asexual reproduction in yeast. Draw diagrams of the observations he must have made from the slide. Name the process also.
You are given balls and stick model of six carbon atoms and fourteen hydrogen atoms and sufficient number of sticks. In how many ways one can join the models of six carbon atoms and fourteen hydrogen atoms to form different molecules of C6H14.
Name the electric device that converts mechanical energy into electrical energy. Draw the labelled diagram and explain the principle involved in this device.
Draw a circuit diagram of an electric circuit containing a cell, a key, an ammeter, a resistor of 4Ω in series with a combination of two resistors (8Ω each) in parallel and a voltmeter across parallel combination. Each of them dissipate maximum energy and can withstand a maximum power of 16W without melting. Find the maximum current that can flow through the three resistors.
With the help of a labelled circuit diagram wire describe an activity to illustrate the pattern of the magnetic field lines around a straight current carrying long conducting wire.
In given figure ∠1 = ∠2 and ΔNSQ ≅ ΔMTR , then prove that ΔPTS ~ ΔPRQ.
(i) Write two observations when lead nitrate is heated in a test tube.
(ii) Name the type of reaction.
(iii) Write a balanced chemical equation to represent the above reaction.
A compound ‘X’ of sodium is used as an antacid and it decomposes on strong heating.
You are provided with 90 mL of distilled water and 10 mL of concentrated sulphuric acid to prepare dilute sulphuric acid.
Two elements X and Y have atomic numbers 12 and 16 respectively. To which period of the modern periodic table do these two elements belong? What type of bond will be formed between them and why? Also give the chemical formula of the compound formed.
(i) Create a terrestrial food chain depicting four trophic levels.
(ii) Why do we not find food chains of more than four trophic levels in nature?
How will you create an artificial aquatic ecosystem, which is self-sustainable?
Explain giving reasons the bending of the shoot tip of a plant towards light source coming from one side of the plant.
It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm.
In the figure given below, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum XY on the screen.
(i) What is visible spectrum?
(ii) Why is red used as the stopping light at traffic signals?
(iii) Two triangular glass prisms are kept together connected through their rectangular side. A light beam is passed through one side of the combination. Will there be any dispersion? Justify your answer.
State the reason for the following: Sodium or potassium metals are kept immersed under kerosene.
State the reason for the following: Hydrogen gas is not evolved when most metals react with nitric acid.
State the reason for the following: An iron strip dipped in a blue copper sulphate solution turns the blue solution pale green.
(i) Consider a conductor of resistance ‘R’, length ‘L’, thickness ‘d’ and resistivity ‘ρ’. Now this conductor is cut into four equal parts. What will be the new resistivity of each of these parts? Why?
Describe the role of Alluri Sitaram Raju in Andhra Pradesh during 1920s.
Describe the incidence of Jallianwala Bagh Massacre.
Why did Europeans flee to America in nineteenth century? Explain.
"India has fairly rich and varied mineral resources across different regions". Support the statement with examples.
Why do banks and cooperative societies need to lend more? Explain.
Why do we need to expand formal sources of credit in India? Explain.
Underemployment continues to be rampant in the rural areas. Suggest any three ways through which employment for rural people can be generated.
Why was the period of 1848 considered as phase of the revolution of the Liberals in Europe? Explain.
Highlight the reasons for the growth of nationalist tensions in the Balkan region before the First World War.
‘The challenge of sustainable development requires control over industrial pollution.’ Substantiate the statement with examples.
Explain with examples the accommodative experience of Belgium for peace and harmony.
‘Democracy is based on the idea of deliberation and negotiation’. Examine the statement.
‘Respect and equal treatment of women are necessary ingredients of a democratic society’. Examine the statement.
Describe the role of technology in promoting globalisation process.
How does valency of an element vary across a period?
A lens produces a magnification of -0.5. Is this a converging or diverging lens? If the focal length of the lens is 6 cm, draw a ray diagram showing the image formation in this case.