General Introduction
- The total number of question is 19.
- Question 1 to question 7 are Very short answer type questions. Answer any Five of these questions in at most one sentence. Each question carries 2 makes.
- Question 8 to question 14 are short answer type questions. Answer any Five questions. Each question carries 3 makes.
- Question 15 to question 19 are Long answer type questions. Answer any three questions. Each question carries 5 makes.
VERY SHORT ANSWER TYPE QUESTIONS :-
Answer any Five Questions
Q1. Write S.I unit of electric charge. What is charge on an electron?
Answer:- The SI unit of electric charges is coulomb ( C ). The charge on an electron is 1.6× 10-9C
Q2. Which physical quantity is measured by using voltmeter? How is a voltmeter connected in electric circuit?
Answer:-
(i) The potential difference is measured by a means of instrument is called a voltmeter.
(ii) The voltmeter is always connected in parallel across the point between which the potential difference is to be measured.
Q3. Give an example of a metal which is found in a liquid stage at room temperature?
Answer:- Mercury ( Hg ) is the metal found in liquid state at room temperature.
Q4. Write the general formula of alkyne.
Answer:- The general formula of alkyne is
Q5. Which plant Mendel Choose for his experiment?
Answer:- Pea plant choose for his experiment.
Q6. Give example of a biodegradable substance?
Answer:- some example of biodegradable substances are:-Vegetable, leaves, cotton etc.
Q7. What do producers depends for their energy.
Answer:- The producer defined for their energy in the process of photosynthesis. Producer required sunlight water and carbon dioxide.
SHORT ANSWER TYPE QUESTIONS:-
Answer any Five questions.
Q8. Define one ampere. Calculate the current in circuit if 500C charge pass through it in 10 minutes.
Answer:- 1 ampere is constituted by the flow of one coulomb of charge per second.
q= 500 C,
t = 10 minutes = 10× 60 sec = 600 Sec
I=q/t
= 500/600 = 0.83
Q9. Explain the following –
A) How does the resistance of a wire change with the charge in its area of cross- section?
Answer:- R ∝1/A , where A cross sectional area. If cross sectional area of a wire is less, its resistance is high. But if cross sectional area of a wire is large its resistance is law.
b) On what factor does the resistance of Conductor depend ?
Answer:- the resistance of a conductor depend on the following factors they are:-
A . The length of the conductor
B. Nature of the material of the conductor
C. The temperature of the conductor
D. The cross section area of the conductor.
Q10. Why are the heating components of electric toaster and electric iron made of some alloy instead of pure metal?
Answer:- The heating components all electric toaster and electric iron made of some alloy instead of pure metal because the pure metal have low melting point and alloy have high melting point, so alloy does not oxidise ( or burn) high temperature.
Q11. Write three environmental friendly practices ?
Answer – The three environmental practices
A ) Avoiding the use of plastic bag and use the cotton bags
B ) Reuse of the plastic bottle
C) Take the cycle inside of using bicycle for transport.
Q12. What do you mean by homologous organ? give an example.
Answer:- they have same origin and structure but perform different function is called homologous organs.
Q13. What is the role of decomposer in ecosystem?
Answer:- The role of decomposer in ecosystem are:-
A ) they clean the environment.
B ) they decompose by variable substances into useful
C) they release nutrients into soil by decomposing date and drawing matter , thus making the soil fertile
D) they maintaining the nutrients by returning back the nutrients in the plant.
Q14. What is an homologous series explain with example?
Answer:- A homologous series for carbon compounds that have different of carbon atom but contains the same functional group.
Eg :- methane, ethane.
LONG ANSWER TYPE QUESTIONS:-
Answer any Three questions.
Q15. Define series combination of resistances. In an electric circuit three resistance whose resistance are one are two are three resistor whose resistance are R1, R2 and R3 respectively . They are connected in series . Drive the expression for the equivalent resistance for the electric circuit.
Answer:-
series combination:- when second end of first resistance ( R1) is connected to the first end of second resistance ( R2) and the second end of second resistance is connected to the first end of third resistance. ( R3) . And their connected in series are called series combination.
Let be the three resistance R1 , R2 and R3 are connected in series.
The potential difference V1, V2 and V3.
Let( I ) current supplied by 2 a battery in the combination.
V1 = IR1 ……. ( i)
V2 = IR2 ………(ii)
V3 = IR3 ………(ii)
V = V1+V2+V3………( iv)
By adding equation 1,2,3
V1+V2+V3= IR1 + IR2 + IR3
V = I ( R1 + R2 + R3 ) ….. { from eq iv }
V/I= R1+ R2+R3
R = R1 + R2 + R3 …….. .. ( R=V/I )
Q16.
Answer:- R1 =5 Ω, R2= 10 Ω, R3= 30 Ω
V= 12V
A) Total resistance
1/R = 1/R1+1/R2+1/R3
=1/5+1/10+1/30
= (6+3+1)/30=10/30=1/3
R=3 Ω ans.
B) Total current in the circuit.
I=V/R
=12/3
=4A ans.
C) Total current ( I1 )through the resistance
R1I_1=V/R_1
=12/5Ω
=2.4A
The current I_2 through the resistance R2.I_2=V/R_2 =12V/10Ω
=1.2A
The current I_3 through the resistance
R3I_3=V/R_3 =12V/30Ω
= 0.4A
Q17. Differentiate between metal and nonmetal on the basis of their chemical properties.
| Metals | Non Metals |
|---|---|
| These are electropositive | These are electronegative |
| These act as good reducing agent | They act has a good oxidizing agent. |
| They form basic oxide | They form acidic oxide. |
Q18. What are trophic level? Give an example of a food change and state the different trophy level in it.
Answer :- Trophic level :- in a food chain, the transfer of food or energy take place at various level this level is known as trophic level.
Example:- Grass. → Dear → Lion
Grass represent 1st trophic level or producer.
Dear represent 2nd trophic level.
Lion represent 3rd trophic level.
Q19. A) what do you mean by dominant traits
Answer:- the trade that appear in the first generation after cross bleeding are called dominant traits.
B) how do Mendel experiment so that traits may be dominant Or recessive.
Answer:- When mendel made a cross between long and dwarf the plant he could get only long plant in the first generation. But when he cross the product of the first generation he got dwarf plant also. Thus, he come to the conclusion that in the first generation only long plants appeared has the trait for length was dominant. However, from the second generation apparance of dwarf plant shows there the trait for b dwarfness was recessive in the first generation.