Pesticides are chemical compounds which are used to control or kill the pets.
This note contains an information about uses of insecticides and their usefulness and negative impact on nature.
Pesticides are chemical compounds which are used to control or kill the pets.
This note contains an information about uses of insecticides and their usefulness and negative impact on nature.
Things to Remember
Pesticides are chemical compounds which are used to control or kill the pets.
Insecticides are used for controlling insects.
Herbicides are used for destroying weeds.
Fungicides are used for killing fungi.
Miticides are used to destroy mites.
MCQs
No MCQs found.
Subjective Questions
Q1:
In the given diagram, PQRS is a square. If PO \(\parallel\) ST and SQ = \(3 \sqrt{2}\) cm then find the area of \( \Delta PQT. \)
Answer: <p><strong>Solution:</strong></p> <p>BD = \(3 \sqrt{2}cm\)<br>BC = CD = AD = AB [\(\therefore\) Sides of square]</p> <p>In right angled \(\Delta\)BCD</p> <p>\begin{align*} (\sqrt{BD} \ )^2 &= (\sqrt{BC} \ )^2 +(\sqrt{CD} \ )^2\\ 3\sqrt{2} &= (\sqrt{BC} \ )^2 +(\sqrt{CD} \ )^2\\ 18 &= 2BC^2\\ BC^2 &= \frac{18}{2} \\ &= 9 \\ &= 3^2\: cm \end{align*}</p> <p>Area of ABCD = 9 cm<sup>2</sup></p>
Q4:
PQRS is a quadrilateral in which PR = 10cm, perpendicular from S and Q on PR are 3.4 cm and 4.6cm respectively. Calculate the area of the quadrilateral.
Answer: <p><strong>Solution:</strong></p> <p>PQ = QR = RS = PS = 6cm \([\because sides\:of\: rhombus ]\)<br>PT = 4 cm<br>Area of rhombus PQRS = ?</p> <p>We know,</p> <p>\begin{align*} Area \: of \: Rhombus\: PQRS &= base \times height\\ &= QR \times PT\\ &= 6 \times 4\\ &= 24\:cm^2 \:\: _{Ans} \end{align*}</p>
Q12:
Adjoining the figure MNRP, is a quadrilateral in which MN\(\parallel \) PR. \(\angle MNR=\angle PRN = 90 º\), NR = 8 cm, and PM = 10 cm, If the area of the quadrilateral MNRP is 72 sq. cm. Calculate the length of MN.
Answer: <p><strong>Solution:</strong></p> <p>Area of the \(\Delta KMN = 30\: cm^2\)<br>\(Area \: of\: the\: \Delta KMV = \frac {1}{2} \Delta KLN \\ [\because Median \: KM\: bisect\: the \: \Delta KLM ]\\ Area \: of \: \Delta KMN = \frac{1}{2}\times 30 = 15 \: cm^2 \:\:_{Ans} \)</p>
Q16:
In the given figure, ABCD is parallelogram in which E is the mid point of DC. If the area of \(\Delta ADE \) is 5 sq. cm. Find the area of the quadrilateral ABCE.
Answer: <p><strong>Solution:</strong></p> <p>AB = 4 cm<br>Area of EBCF = ?</p> <p>\begin{align*} Area \: of \: square ABCD &= (AB)^2 \\ &= 4^2 \\ &= 16 \: cm^2 \\ \\ Area \: of \: parallelogram \: EBCF &= Area \: of \: square \: ABCD \\ &= 16 \: cm^2 \:\: [\because \text{Standing n same base and between same parallel lines}] \end{align*}</p>
Q20:
In the given figure, PQRS is a parallelogram in which T is the middle of PS. If the area of the \(\Delta PTQ \: is \: 6 \:cm^2,\) what will be the area of the quadrilateral QTSR.
Answer: <p><strong>Solution:</strong></p> <p><strong>Given:</strong> \(\Delta ABC \) and parm. EBCF are on the same base and between the same parallels.</p> <p><strong>To prove:</strong>\(\Delta ABC = \frac{1}{2} \: parm. \:EBCF \)</p> <p><strong>Construction:</strong> Draw CD parallel to BA and to meet AF at D</p> <table width="454"><tbody><tr><td><strong>S.N</strong></td> <td><strong>Statements</strong></td> <td><strong>Reasons</strong></td> </tr><tr><td>1</td> <td>ABCD is a parallelogram.</td> <td>By construction and given.</td> </tr><tr><td>2</td> <td>\(\Delta ABC = \frac{1}{2}\)parm ABCD</td> <td>Diagonal AC bisects parm ABCD.</td> </tr><tr><td>3</td> <td>Parm ABCD = Parm EBCF</td> <td>They stand on the same base BC and between the same parallels AF and BC.</td> </tr><tr><td>4</td> <td>\(\Delta ABC = \frac{1}{2} parm. EBCF \)</td> <td>From statement (2) and (3)</td> </tr></tbody></table><p>\( \:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\: _{Proved}\)</p>
Q26:
Prove that the parallelograms on the same base and between the same parallels are equal in area.
Answer: <p><strong>Solution:</strong></p> <p><strong>Given:</strong> Parallelograms ABCD and EBCF on the same base BC and between the same parallels AF and BC.<br><strong>To prove:</strong> Parm. ABCD = Parm. EBCF<br><strong>Proof</strong></p> <table width="571"><tbody><tr><td><strong>S.N</strong></td> <td><strong>Statements</strong></td> <td><strong>Reasons</strong></td> </tr><tr><td>1</td> <td>In \(\Delta ABE \:and\: \Delta CDF \\ (i) \angle BAE = \angle CDF\\(ii) \angle BEA = \angle CFD\\ (iii) AB = DC \)</td> <td>\(\\ (i) Corresponding \:angles\\Corresponding\:angles\\ (iii) Opposite \: sides \: of \: para \: ABCD \)</td> </tr><tr><td>2</td> <td>\(\Delta ABE≅ \Delta CDF\)</td> <td>by A.A.S axiom</td> </tr><tr><td>3</td> <td>\(\Delta ABE = \Delta CDF\)</td> <td>Area of congruent triangles</td> </tr><tr><td>4</td> <td>\(Trapezium\: ABCF - \Delta CDF = Trapezium\: ABCF - \Delta ABE \)</td> <td>Subtracting equal triangles from same figure.</td> </tr><tr><td>5</td> <td>Parm. ABCD = Parm. EBCF</td> <td>From Statement (4)</td> </tr></tbody></table>
Videos
Triangle area proofs | Perimeter, area, and volume | Geometry
Area of triangles and quadrilaterals
Types of quadrilateral
Insecticides and Pesticides
Pesticides
Pesticides are chemical compounds which are used to control or kill the pets. Depending upon the types of organism, pesticides are classified as follows:
Insecticides: These pesticides are used for controlling insects.
Herbicides:These pesticides are used for destroying weeds.
Fungicides: These pesticides are used for killing fungi.
Miticides: They destroy mites.
Insecticides:
The poisonous chemicals which are made by humans and used to control or kill the insects are called insecticides.
Organic insecticides: Those insecticides which are obtained from the living source are called organic insecticides. Mainly, there are three types of organic insecticides. They are:
Organochloride
Example: DDT (Dichloro Diphenyl Trichloroethane)
BHC ( Benzene Hexachloride)
Organophosphorous
Example: Malathion, Parathion
Carbonate insecticides
Baygon
Temik
Dinetan
Inorganic insecticides
Those insecticides derived from minerals are called inorganic insecticides.
Example: calcium arsenate, lead arsenate
Advantages of using insecticides
They kill or destroy harmful insects.
They can destroy all the stages of the lifecycle of harmful insects. As a result, there is increase in crop yield.
They help to control several diseases by killing germs.
Disadvantages of using insecticides
Most of the insecticides are non biodegradable. Hence, they are harmful to insects and plants.
Insecticides leave harmful deposits on food crops. The use of such food crops has adverse effects on the health of human beings and all other animals.
They can pollute lakes, ponds, streams, etc.
They destroy useful insects also.
The spray of insecticides can affect plants and animals too.
Precautions in using insecticides:
They should be kept away from the reach of children and ignorant persons
The name of the insecticides should be labelled clearly.
While applying it, the mouth, nose and eyes should be well covered.
It should be used in little amount.
We should be careful while using it.
After spraying or dusting it, hands and other body parts must be properly cleaned.