Conservation of Plants and Animals class 8

 Que:1 Why is the conservation of biodiversity important ?

Que 2 How can we proptect wildlife?

Que 3 What do you mean by biosphere reserve?

Que 4 Explain how deforestation associated with global warming?

Que 5 How does deforestation lead to  frequenr flood and drought?

Que 6  What is Red Data Book?

Que 7  What is the major threat to survival of organism?

Que 8  Name the part of earth which supports the biodiversity.

Que 9  Give examples of two endemic flora

Que 10  Name the plant found in Satpura forest.

Que 11.  How do we protect wildlife?

Que 12  What do you mean by migration? Write causes of migration.

Que 13  What do you meant by Forest Conversation Act?

Que 14  Name two threatened wild animals.

Que 15  What is the tiger Project? When it was launched? 

Chemical effects of electric current class 8th Science

1. What do you mean by gold plating?

2.What happens when electrodes are immersed in water and a current is passed?

3.Why tap water is always good conductors?

4.Explain the functioning of a LED.

5.Is it possible for an electric tester to detect weak current also, if no how can we detect weak current flowing in a circuit?

6.What do you mean by electrolysis and electrolytes?

7.In case of fire before the fireman used the water hoses, they shut off the main electrical supply of the area, why so?

8.In which case the compass needle will deflect more: by testing sea water or by testing drinking water?

9.Show that lemon juice and vinegar are good conductors of electricity.

10.The ordinary water can conduct electricity while distilled water does not. Explain why.

11. What is chemical effect of electricity? Give some examples of chemical effects.

12.Explain the process of electroplating, along with its advantages and uses.

13.Prepare a tester to test conduction based on magnetic effect of the electricity.

Class 8th Comparing Quantities Ncert

 Que :1 Convert the following ratios to percentages:

(a) 3 : 4
(b) 2 : 3

Que 2 : A football team won 10 matches out of the total number of matches they played. If their win percentage was 40, then how many matches did they play in all?

Que 3: If Chameli had ₹ 600 left after spending 75% of her money, how much did she have in the beginning?

Que 4: A man got a 10% increase in his salary. If his new salary is ₹ 1,54,000, find his original salary.

Que 5: The cost of an article was ₹ 15,500. ₹ 450 were spent on its repairs. If it is sold for a profit of 15%, find the selling price of the article.

Que 6: A VCR and TV were bought for ₹ 8,000 each. The shopkeeper made a loss of 4% on the VCR and a profit of 8% on the TV. Find the gain or loss per cent on the whole transaction.

QUe 7: A milkman sold two of his buffaloes for ₹ 20,000 each. On one he made a gain of 5% and on the other a loss of 10%. Find his overall gain or loss.

Que 8: The price of a TV is ₹ 13,000. The sales tax charged on it is at the rate of 12%. Find the amount that Vinod will have to pay if he buys it.

Que 9: I purchased a hair-dryer for ₹ 5,400 including 8% VAT. Find the price before VAT was added.

Que 10: Kamala borrowed ₹ 26,400 from a Bank to buy a scooter at a rate of 15% per annum compounded yearly. What amount will she pay at the end of 2 years and 4 months to clear the loan?

Que 11: Find the amount and the compound interest on ₹ 10,000 for 1

12 years at 10% per annum, compounded half yearly. Would this interest be more than the interest he would get if it was compounded annually?

Que 12: The population of a place increased to 54,000 in 2003 at a rate of 5% per annum.
(i) Find the population in 2001.
(ii) What would be its population in 2005?

Que 13: A scooter was bought at ₹ 42,000. Its value depreciated at the rate of 8% per annum. Find its value after one year.

class 8 (quad imp ques)

Q-1 In the following figure,FD||BC||AE and AC||ED. Find the value of x.                 

Q-2 ABCD is a trapezium such that AB||CD, ∠A : ∠D = 2 :1, ∠B : ∠C = 7 : 5. Find the angles of the trapezium.

Q-3 ABCD is a parallelogram. Find the value of x, y and z

Q-4 The adjacent angles of a parallelogram are (2x – 4)° and (3x – 1)°. Find the measures of all angles of the parallelogram.

Q-5 In a quadrilateral ABCD, ∠D is equal to 150° and ∠A = ∠B = ∠C. Find ∠A, ∠B and ∠C.

Q. 6: In quadrilaterals, 
(i) which of them have their diagonals bisecting each other?
(ii) which of them have their diagonal perpendicular to each other?
(iii) which of them have equal diagonals?

Q-7 Find the sum of all internal angle of a pentagon that is regular. 

Q-8 If an exterior angle of a regular polygon is 45°, then find the number of its sides.

Q-9 If an interior angle of a regular polygon is 162°, then find the number of its sides.

Q-10 Find the measure of an interior angle of a regular polygon having 15 sides.
 

Class 8th (linear important questions)

 Q-1 A lady went to a bank with Rs. 1,00,000. She asked the cashier to give her Rs. 500 and Rs. 1,000 currency notes in return. She got 175 currency notes in all. Find the number of each kind of currency notes

Q-2 Denominator of a number is 4 less than its numerator. If 6 is added to the numerator it becomes thrice the denominator. Find the fraction

Q-3 Anima left one-half of her property to her daughter, one-third to her son and donated the rest to an educational institute. If the donation was worth Rs. 1,00,000, how much money did Anima have?

Q-4 After 12 years, Kanwar shall be 3 times as old as he was 4 years ago. Find his present age

Q-5 Sum of the digits of a two-digit number is 11. The given number is less than the number obtained by interchanging the digits by 9. Find the number.

Q-6 The present age of father is four times the age of his son. After 10 years, age of father will become three times the age of his son. Find their present ages.

Q-7 The age of A is five years more than that of B. 5 years ago, the ratio of their ages was 3:2. Find their present ages.

class 8th (linear and Quad )

 

Q -1 Deveshi has a total of $Rs590$ as currency notes in the denominations of $Rs50,Rs20$ and $Rs10$. The ratio of the number of $Rs50$ notes and $Rs20$ notes is $3:5$. If she has a total of $25$ notes, how many notes of each denomination she has?

Q-2  The organisers of an essay competition decide that a winner in the competition gets a prize of Rs. $100$ and a participant who does not win gets a prize of Rs. $25$. The total prize money distributed is Rs. $3000$. Find the number of winners, if the total number of participants is $63$.

Q 3 Baichung's father is $26$ years younger than Baichung's grandfather and $29$ years older than Baichung. The sum of the ages of all the three is $135$ years. What is the age of each of each one of them?

Q 4 One of the two digits of a two digit number is three times the other digit. If you interchange the digits of this two digit number and add the resulting number to the original number, you get $88$. What is the original number?

Q5  There is a narrow rectangular plot, reserved for a school, in Mahuli village. The length and breadth of the plot are in the ratio $11:4$. At the rate Rs. $100$ per metre it will cost the village panchayat Rs. $75000$ to fence the plot. What are the dimensions of the plot?

Q6 Half a herd of deer are grazing in the field and three fourths of the remaining are playing nearby. If the remaining 9 are drinking water from a pond ,Find the number of deer in the herd.

Q 7 Present ages of Anu and Raj are in ratio 4:5. eight years from now the ratio of their ages will be 5:6.find their present ages
Q 8 Find the angle measure x in the following figures.

(a)	(b)
(c)	(d)

Q 9 Find the measure of each exterior angle of a regular polygon of

(i) 9 sides

(ii) 15 sides

Q 10 How many sides does a regular polygon have if each of its interior angles is 165°?

Q 11 Consider the following parallelograms. Find the values of the unknowns x, y, z.

(i)	(ii)
	(iv)

Q 12 Find the measure of ∠P and ∠S, if  in the following figure

Q13 

In the above figure both RISK and CLUE are parallelograms. Find the value of x