Give any two ways in which biodegradable substances would affect the environment.
The biodegradable substances would affect the environment and they can easily degraded by the natural actions. Two ways are following in which biodegradable substances affect the environment:-
Biodegradable substances decomposed easily, they are less harmful than the non- biodegradable substances. When the decomposition process occurs through the microbial action or the radiations they produce foul smell. Biodegradable wastes like green waste, food waste, paper etc. pollutes the environment only when they are present in the excess amount and produce some harmful gases like ammonia, methane gas, carbon dioxide that may cause global warming.
When the decomposition process occurs by some microbes of biodegradable wastes, which contains houseflies, mosquitoes which carry the parasites which are the main causes of the human diseases.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
What is the role of the acid in our stomach?
How is food transported in plants?
Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal
(d) AgNO3 solution and copper metal.
What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
List the properties of magnetic field lines.
Design an experiment to demonstrate hydrotropism.
Compare the power used in the 2 Ω resistor in each of the following circuits:
(i) a 6 V battery in series with 1 Ω and 2 Ω resistors, and (ii) a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
How do we detect the smell of an agarbatti (incense stick)?