Chapter 4: Carbon and its Compounds)
Chapter 5: Periodic Classification of Elements
Chapter 8: How do Organisms Reproduce
Chapter 10: Light - Reflection and Refraction
Chapter 11: Human Eye and Colorful World
Chapter 15: Our Environment
Chapter 16: Management of Natural Resources
For full solution Visit
Other Educational Portals
CBSE PHYSICS| CBSE MATH STUDY | CHEMISTRY ADDA | CBSE ADDA
Class-IX Math Chapter : Area of Parallelogram and Triangles
Points to Remember -
Solved Theorem and some examples to illustrate the use of these theorem
Points to Remember :
1. Two congruent figures must have equal areas. However, two figures having equal areas need not to be congruent.
2. Two figures are said to be on the same base and between the same parallels, if they have a common base and the vertices (or the vertex) opposite to the common base of each figure lie on a line parallel to the base.
3. Parallelograms on the same base and between the same parallels are equal in area.
4. Area of parallelogram = Base × corresponding height.
5. Parallelograms on the same base (or equal bases) and having equal areas lie between the same parallels.
6. Two triangles on the same base (or equal bases) and between the same parallels are equal in area.
7. Two triangles having the same base (or equal bases) and equal areas lie betwen the same parallels.
8. Area of Triangle = 1/2× Base × corresponding height.
9. Area of a Rhombus= 1/2× product of diagonals.
10. Area of a Trapezium= 1/2× (sum of the parallel sides) × (distance between them).
11. A median of a triangle divides it into two triangles of equal area.
12. The diagonals of a parallelogram divides it into four triangles of equal area
Activity related to Area of parallelogram and triangle
NCERT Solutions Topper learning
Area of Parallelogram and Triangle Test paper
IX Chapter-15 : PROBABILITY - NCERT solution - Key points CCE Test papers Solved Theorem and Illustrated examples
Points to Remember :
1. An activity which gives a result is called an experiment.
2. An experiment which can be repeated a number of times under the same set of conditions, and the outcomes are not predictable is called a Random Experiment.
3. Performing an experiment is called a trial.
4. Any outcome of an experiment is known as an event.
5. In n trials of a random experiments, if an event E happens m times, then the probability of happening of E is given by,
P (E)= Number of outcomes favour to E /Total number of possible outcomes
6. For any event E, which is associated to an experiment, we have 0 lessthan and equal P(E) greater and equalto 1.
7. If E1, E2, E3, ....., En are n elemantary events associated to a random experiment, then
P(E1) + P(E2) + P(E3) + ........... + P(En) = 1
1. A number is chosen from 1 to 20. Find the probability that the number chosen is :
(i) a prime number (ii) a composite number
(iii) a square number (iv) an odd number
(v) an even number (vi) number between 7 and 14
2. A bag contains 9 red and 6 blue balls. Find the probability that a ball drawn from a bag at random is (i) Red ball (ii) blue ball
3. In a sample of 500 items, 120 are found to be defective. Find the probability that the item selected at random is (i) defective (ii) non-defective
4. In a school of 1800 students, there are 875 girls. Find the probability that a student chosen at random is (i) a boy (ii) a girl
5. In a cricket match, a batsman hit a boundary 12 times out 45 balls he plays. Find the probability that hedid not hit a boundary.
6. A coin is tossed 700 times and we get
head : 385 times; tail : 315 times.
When a coin is tossed at random,what is the probability of getting : (i) a head? (ii) a tail?
7. Two coins are tossed 600 times and we get
two heads : 138 times, one head : 192 times ; no head : 270 times.
When two coins are tossed at random, what is the probability of getting :
(i) 2 heads? (ii) 1 head? (iii) no head?
8. Three coins are tossed 250 times and we get:
3 heads : 46 times; 2 heads : 56 times; 1 head : 70 times; 0 head : 78 times.
When three coins are tossed at random, what is the probability of getting :
(i) 3 heads ? (ii) 2 heads? (iii) atleast 2 heads? (iv) atmost 2 heads?
9. Find the probability that a leap year, selected at random will have 53 sundays
10. A bag contains 10 white balls and x black balls. If the probability of drawing a black ball is double that of a white ball, find X
Sample- Paper- Class – X Subject –Physics Light: Reflection and Refraction
Very short Answer
1. What is radius of plane mirror?
2. What is angle of reflection for a ray falling normally on a plane mirror?
3. Why do we use convex surface for side view mirror?
4. Can a virtual image be photographed?
5. What is the power of a plane mirror?
6. When the angle of incidence is 90 deg., what is the angle of refraction?
7. What is the value of refractive index of air?
8. What is the magnification produced by a plane mirror?
9. Define power. Give its S.I unit?
10. What is power of sunglass?
Download full paper:
You may also like
10th Light – Reflection and Refraction Key concepts and terms
X Physics Reflection and Refraction Solved questions
GIST OF THE CHAPTER Light Refraction and Refraction
1. The first theory of light was put forward by Newton. This theory treats light as a particle called corpuscle.
2. We can say that light propagates as a wave and is emitted and absorbed as a particle.
3. One may regard light as having dual nature.
4. Maxwell proved that light has wave nature; it is an electromagnetic transverse wave, which does not require medium to propagate.
5. The speed of light in air is a universal constant. It has a value of 3x108m/s.
6. Light gets reflected when it falls on polished surface; like mirror.
7. Light suffers refraction when it travels from one medium to another.
8. There is a change in the wavelength of light when it moves from one medium to another.
9. The image is unmagnified, virtual and erect in a plane mirror.
10 Focal length of a plane mirror is infinity.
11. Power of a plane mirror is zero.'
12. It should be noted that, if the spherical lenses are surrounded by a material with a refractive index greater than that of the lens, the convex lens gets converted into a concave lens or vice-versa.
f = R/2
1 / v + 1 / u = 1 / f = 2 /R
M = h2 /h1 = -v/u
n = c/v
1n2 = 1/2n1
1n2 = n2/n1= sin i/sin r
a n w = x/y
1/v –1/u = 1/f
m =I/O = h2 /h1 = v/u
P= 1/f metre
P = p1 + p2 + p3 + …….
VERY SHORT QUESTIONS CARRYING 1 MARK EACH.
1. Out of convex mirror and concave mirror, whose focus is situated behind the mirror?
Ans: The focus of convex mirror is situated behind it.
2. For what position of an object, a concave mirror forms an enlarged virtual image?
Ans: Object between pole (P) and focus (F) of the concave mirror.
3. If the focal length of a concave mirror is 25cm. What is its radius of curvature?
Ans: Focal length = Radius of curvature / 2
25 = R / 2
R = 25 X 2 = 50cm.
4. A ray of light falls on a mirror normally. What are the values of angle of incidence and the angle of reflection?
Ans: Both angle of incidence and the angle of reflection are zero.
5. What is the focal length of a plane mirror?
6. Which spherical mirror is called a divergent mirror?
Ans: A convex mirror is called a divergent mirror.
7. What is the angle of incidence, when a ray of light falls on the spherical mirror from its centre of curvature?
Ans: The angle of incidence is zero, when a ray of light falls on the spherical mirror from its centre of curvature.
8. Name the type of mirror that always forms a virtual image for a real object?
Ans: Convex Mirror.
9. State the relation between radius of curvature and focal length of spherical mirrors.
Ans: Radius of curvature = 2 X focal length.
R = 2f.
10. Which of the two is a diverging lens? Convex lens (or) Concave lens.
Ans: Concave lens.
11. If an object is placed at a distance of 10cm in front of a plane mirror, how far would it be from its image?
Ans: The object would be at a distance of 20cm from its image.
12. Name the physical quantity which remains the same when light goes from one medium to another?
Ans: Frequency of light.
13. Define power of a lens.
Ans: The reciprocal of the focal length of the lens is called power of a lens. P = 1/f
14. Calculate the power of a convex lens of focal length 25cm?
Ans: Focal length f = 25cm.
Power = 1/.25 = 100/25 = +4D.
15. Name the phenomenon responsible for the following affect.
Ans: When we sit in front of a plane mirror and write with our right hand, it appears in the mirror that we are writing with the left hand.Ans: Lateral Inversion
16. Define Refractive Index
Ans: It is the ratio of speed of light in vacuum to the speed of light in medium is called Refractive index.
17. Why is the convex lens also known as a converging lens?
Ans: A convex lens is also known as a converging lens because it converges a parallel beam of light raying passing through it.
18. Give the ratio of velocities of two light waves travelling is vacuum and having wave lengths 4000A and 8000A.
Ans: In Vacuum, light of all the wave lengths travel with the same velocity i.e. 3 X 108 m/sec.
19. For what angle of incidence, the lateral shift produced by parallel sided glass plate is zero?
Ans: For i = 0.
20. What are the factors on which the lateral shift depends?
Ans: Thickness of the refracting medium, angle of incidence and its refractive index.
21. What is the power of a plane glass plate?
22. An object is placed at the focus of a concave lens. Where will its image be formed?
Ans: The rays will appear to come from infinity. Therefore, a virtual image will be formed at infinity.
23. What is the unit of power of a lens?
24. Why the stars appear to twinkle?
Ans: The twinkling of a star is due to the atmospheric refraction of star’s light.
25. What is the value of refractive index of air?
More study material visit :
10th Science - Light Refraction and Refraction10th Light – Reflection and Refraction Key concepts and terms
X Physics Reflection and Refraction Solved questions-1
The Ministry of Human Resource Development, Govt. of India has entrusted the responsibility of conducting the Central Teacher Eligibility Test (CTET) to the Central Board of Secondary Education, Delhi which will be held on 29.01.2012 (Sunday).
1. The CTET shall apply to schools of the Central Government (KVS, NVS, Tibetan Schools, etc.) and schools under the administrative control of UT of Chandigarh and Andaman & Nicobar Islands.
2. CTET may also apply to the unaided private schools, who may exercise the option of considering the CTET.
3. Schools owned and managed by the State government/local bodies and aided schools shall consider the TET conducted by the State Government. However, a State Government can also consider the CTET if it decides not to conduct the State TET.
Cost of CTET Information Bulletin and Application Form
(i) For General/OBC candidates Rs.500/-
(ii) For SC/ST/Differently abled candidates Rs.250/-
Sale of CTET Information Bulletin and Application Form: 05.11.2011 to 25.11.2011
Date for making on-line application: 01.11.2011 to 25.11.2011
Last date for receipt of application form in CBSE: 30.11.2011 (online and offline both)
Note: 7 days grace time i.e. up to 07.12.2011 for receipt of Application Form will be allowed
to the candidates belonging to remote areas viz. Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, Lahaul and Spiti District and Pangi Subdivision of Chamba district of Himachal Pradesh, Andaman & Nicobar Island and
Schedule of Examination
DATE OF EXAMINATION PAPER TIMING DURATION
29.01.2012 PAPER - I 10.00 TO 11.30 HOURS 1.30 HOURS
29.01.2012 PAPER - II 13.00 TO 14.30 HOURS 1.30 HOURS For full information and previous year question papers paper visit CTET
Example 1 :There are 4 red balls and 3 green balls in a bag. One ball is taken out at random.What is the probability of getting a red ball ?
Total no.of balls = 4+3 = 7
Favourable balls = 4 (as there are 4 red balls )
Required Probability = Total no. of fav. balls /Total no. of balls = 4/7
Example 2.What is the probability of not getting a red ball ?
Total no.of balls = 4+3 = 7
Favourable balls = 3 (as there are 3 balls other than red balls )
Required Probability = Total no. of fav. balls /Total no. of balls = 3/7
Example 3 :There are 4 red balls , 5 blue balls and 3 green balls in a bag. One ball is taken out at random.What is the probability of getting a red ball ?
Total no.of balls = 4+5+3 = 12
Favourable balls = 4 (as there are 4 red balls )
Required Probability = Total no. of fav. balls /Total no. of balls = 4/12=1/3
Example 4. What is the probability of not getting a red ball ?
Total no.of balls = 4+5+3 = 12Favourable balls = 8 (as there are 8 balls other than red balls )Required Probability = Total no. of fav. balls /Total no. of balls = 8/12 =2/3
Example 5. What is the probability of not getting a red or a green ball ?
Total no.of balls = 4+5+3 = 12
Favourable balls = 9 (as there are 4 red balls and 5 green balls )
Required Probability = Total no. of fav. balls /Total no. of balls = 9/12 =3/4
For more solved questions Visit: http://jsuniltutorial.weebly.com/probability.html
Practice Test paper
1. Two dice are thrown once. What is the probability of getting a doublet?
2. A jar contains 54 marbles of colour blue, green and white. The probability of selecting a blue marble at random from the jar is 1/3 and the probability of selecting a green marble at random is 4/9. How many white marbles do the jar contains?
3. In a leap year, find the probability that there are 53 Sundays in the year.
4. A letter is chosen at random from the word MISSISSIPPI. Find the probability of getting
(i) a vowel
( ii) a consonant.
5. A bag contains 4 whit balls, 6 red balls and 7 black balls. One ball is drawn at random from the bag. What is the probability that the ball drawn is
i) not a black ball
ii) neither white nor black
iii) red or white.
6. A box has cards numbered from 20 to 100. Cards are mixed thoroughly and a card is drawn from the box at random. Find the probability that the number on the card drawn from the box is
i) an odd number
ii) a perfect square number and
iii) a number divisible by 7.
Blog Posts Categories
Join Us For Update
I am a school teacher and serving CBSE students community since 1995.