CBSE Pathshala

IX The Cell & Fundamental Unit of life Question :    Why is the cell known the 'fundamental and structural unit of life ' Ans: ell is called as the structural and functional unit of the living organism because it the smallest living entity that is capable of an independent existence. Separated cell organelles cannot be said to be living and are not capable of independent existence. Question :  what is a semi permeable membrane? what are the differences between semi permeable membrane and selectively permeable membrane? Ans: a semi permeable membrane is a membrane that allows only the entry of substances that are helpful for the body. a semi permeable membrane is also called a selectively permeable membrane. Question :     Which cell in the human body does not have the mitochondria? Ans: Mature erythrocytes don't have mitochondria Question :   What are plastids? Write their functions? Ans: Plastids are double membrane organelle...

Biology assignment Chapter: Tissues  Q1 Plant and animal tissues are different . Comments. Q2 What is the meristamatic tissue ? what are its characteristics ? Q3 Describe the occurrence of apical. Lateral and intercalary meristems . Q4 Define permanent tissue . What are different categories of permanent tissue . Q5 Give distribution ,types and function of parenchymatous tissues. Q6 How is collenchymas different from sclerchma ? Q7 Describe complex permanent tissue ? Q8 What are the different compounds of xylem and phloem ? Q9 Give on outline classification of animals tissue. Q10 Give characteristics and types of the epithelial tissue . Q11 Diagrammatically show the difference in the three types of muscle fibres . Q12 Where are fats stored in our body . Define their structure . Q13 What are the type...

If a line divides any two sides of a triangles proportionally then the line is parallel to the third side Statement:   If a line divides any two sides of a triangles proportionally (in same ratio), then the line is parallel to the third side. Proof:   We are given ABC   AD / BD = AE / CE We have to prove: DE is parallel to BC Let DE's not parallel to BC then an another line DE' is parallel to BC. Now AD / BD = AE / CE [Given] And AD / BD = AE' / CE' [ Thales Theorem ] Therefore AE / CE = AE' / CE' i.e. AE / CE + 1 = AE' / CE' + 1 i.e. AE + CE / CE = AE' + CE' / CE'   i.e. CE = CE' But this is not possible until E and E' is coincident. Thus, our assumption is wrong and DE is parallel to BC. X Triangles :Criteria for Similarity of Triangles Solved:    10th math Triangles Thales theorem   10th math Converse of Thales theorem   Angle bisector theorem   10th math SAS similarity of triangle 10th SSS similarit...

CBSE TEST PAPER MATHEMATICS (Class-10) SIMILAR TRIANGLE CBSE TEST PAPER MATHEMATICS (Class-10) SIMILAR TRIANGLE Chapter : Triangles  1. In  Δ  PQR, given that S is a point on PQ such that ST  II  QR and PS/SQ=3/5 If PR = 5.6 cm, then find PT. 2. In Δ ABC, AE is the external bisector of <A, meeting BC produced at E. If AB = 10 cm, AC = 6 cm and BC = 12 cm, then find CE. 3. P and Q are points on sides AB and AC respectively, of ΔABC. If AP = 3 cm,PB = 6 cm, AQ = 5 cm and QC = 10 cm, show that BC = 3 PQ. 4. The  image of  a tree on the film of a camera is of length 35 mm, the  distance from  the lens to the film is 42 mm and the distance from the lens to  the tree  is 6 m. How tall is the portion of the tree being photographed? 5. D is the midpoint of the side BC of Δ ABC. If P and Q are points on AB and on AC such that DP bisects <BDA and DQ bisects <ADC, then prove t...

CCE helps in improving student’s performance by identifying his/her learning difficulties at regular time intervals right from the beginning of the academic session and employing suitable remedial measures for enhancing their learning performance.                                                                                                                       The scheme of continuous and comprehensive evaluation has inbuilt flexibility for schools to plan their own academic schedules as per specified guidelines on CCE. How will CCE Reporting System help us? Regular formative assessments made possible through an easy data management system Recording the performance of students at ...

Q. If the magnetic field and the direction of movement of conductor is parallel,  then in what direction does the induced current flows ?  Ans: The directions of current, field and force are always perpendicular to each other on account of the Fleming's rule, none of them can be  parallel .  Q. If the direction of current and  magnetic field  is  parallel  the in which direction does the force on the conductor acts?  Ans: The directions of current, field and force are always perpendicular to each other on account of the Fleming's rule, none of them can be  parallel .  Q. Consider a circular loop of wire lying in  the plane  of the table and current is passed thru  the loop  clock wise then by applying right hand rule find the direction of  magnetic field  lines inside and outside  the loop ?  Ans: According to the right hand thumb rule, the direction of  the magnetic  field would be ...

1. Define : gravitation, gravity and gravitational force. 2. State the universal law of gravitation and its mathematical form. 3. In what source is ‘G’ universal? 4. What happens to the force of attraction between two objects when (i) Their mass are halved? (ii) Distance between them is increased to 4 times its previous value. (iii) Distance between them as well as each of the mass is increase to 4 times. 5. If the distance between two bodies is increased 4 times by what factor should the mass of the bodies be altered so that the gravitational force between them remains the same? 6. What is the force between two spheres weighing 20 kg each and placed 50 cm apart? 7. A sphere of mass 40 kg is attracted by another sphere of mass 15 kg when their centres are 0.2m apart with force of 9.8 x 10-7 N. Calculate value of ‘G’. 8. Find the distance between two stones each of mass 2 kg so that the gravitational force between them is 1N. 9. Gravitational force between two object...

Importatant Terms, Definitions and Results To locate the position of an object or a point in a plane, we require two perpendicular lines, one of them is horizontal and the other is vertical. The horizontal line is called the x-axis and the vertical line is called the y-axis. We call the plane, the cartesian plane, or the coordinate plane or the xy-plane. The axes are called the coordinate axes. The point of intersection of the axes (x-axis and y-axis) is called the origin. The coordinate axes divide the plane into four parts, called quadrants. The distance of a point from the y-axis is called its x-coordinate or abscissa. The distance of a point from the x-axis is called the y-coordinate or ordinate. If x ≠ y, then the position of (x, y) in the cartesian plane is different from the position of (y, x). It means the order of x and y is important in (x, y). Therefore, (x, y) is called an ordered pair.  A point in a plane can be represented by an ordered pair (x, y), wher...

Proof of this factor theoremLet p(x) be a polynomial of degree greater than or equal to one and a be areal number such that p(a) = 0. Then, we have to show that (x – a) is a factor of p(x). Let q(x) be the quotient when p(x) is divided by (x – a). By remainder theorem Dividend = Divisor x Quotient + Remainder p(x) = (x – a) x q(x) + p(a) [Remainder theorem] ⇒ p(x) = (x – a) x q(x) [p(a) = 0] ⇒ (x – a) is a factor of p(x) Conversely, let (x – a) be a factor of p(x). Then we have to prove that p(a) = 0 Now, (x – a) is a factor of p(x) ⇒ p(x), when divided by (x – a) gives remainder zero. But, by the remainder theorem, p(x) when divided by (x – a) gives the remainder equal to p(a). ∴ p(a) = 0 Proof of remainder theorem.Let q(x) be the quotient and r(x) be the remainder obtained when the polynomial p(x) is divided by (x–a). Then, p(x) = (x–a) q(x) + r(x), where r(x) = 0 or some constant. Let r(x) = c, where c is some constant. Then p(x) = (x–a) q(x) + cPutting x...

1. The area of a triangle is 30 cm2. Find the base if the altitude exceeds the base by 7 cm.[ 5 cm , 12 cm.] 2. From a point in the interior of an equilateral triangle, perpendiculars drawn to the three sides are 8 cm, 10 cm and 11 cm respectively. Find the area of the triangle. [486.1 cm2] 3. The difference between the sides at right angles in a right-angled triangle is 14 cm. The area of the triangle is 120 cm2. Calculate the perimeter of the triangle. [24 cm, 10 cm, 60 cm.] 4. Find the percentage increase in the area of a triangle if its each side is doubled? [300%] 5. Calculate the area of the triangle whose sides are 18 cm, 24 cm and 30 cm in length. Also, find the length of the altitude corresponding to the smallest side of the triangle. 6. The sides of a triangle are 10 cm, 24 cm and 26 cm. Find its area and the longest altitude. 7. Two sides of a triangular field are 85 m and 154 m in length, and its perimeter is 324 cm. Find (i) the area of the field, and (ii) the ...