CBSE X Questions
Write the smallest number which is divisible by both 306 and 657
Write the smallest number which is divisible by both 306 and 657.
Read more …The probability of selecting a blue marble at random from a jar
The probability of selecting a blue marble at random from a jar that contains only blue, black and green marbles is 1/5. The probability of selecting a black marble at random from the same jar is 1/4 . If the jar contains 11 green marbles, find the total number of marbles in the jar.
Read more …Find the value of k so that the pair of equations x + 2y = 5 and 3x + ky + 15 = 0
Find the value(s) of k so that the pair of equations x + 2y = 5 and 3x + ky + 15 = 0 has a unique solution.
Read more …The larger of two supplementary angles exceeds the smaller
The larger of two supplementary angles exceeds the smaller by 18°. Find the angles.
Read more …Sumit is 3 times as old as his son. Five years later
Sumit is 3 times as old as his son. Five years later, he shall be two and a half times as old as his son. How old is Sumit at present ?
Read more …Prove that 2 + 5√3 is an irrational number
Prove that 2 + 5√3 is an irrational number, given that √3 is an irrational number.
Read more …Using Euclid’s Algorithm, find the HCF of 2048 and 960
Using Euclid’s Algorithm, find the HCF of 2048 and 960.
Read more …Two right triangles ABC and DBC are drawn on the same hypotenuse
Two right triangles ABC and DBC are drawn on the same hypotenuse BC and on the same side of BC. If AC and BD intersect at P, prove that AP × PC = BP × DP.
Read more …Diagonals of a trapezium PQRS intersect each other at the point O
Diagonals of a trapezium PQRS intersect each other at the point O, PQ ∥ RS and PQ = 3RS. Find the ratio of the areas of triangles POQ and ROS.
Read more …In Figure, PQ and RS are two parallel tangents to a circle with centre O
In Figure, PQ and RS are two parallel tangents to a circle with centre O and another tangent AB with point of contact C intersecting PQ at A and RS at B. Prove that ∠AOB = 90º.
Find the ratio in which the line x – 3y = 0 divides the line segment
Find the ratio in which the line x – 3y = 0 divides the line segment joining the points (–2, –5) and (6, 3). Find the coordinates of the point of intersection.
Read more …
In Figure, a square OABC is inscribed in a quadrant OPBQ
In Figure, a square OABC is inscribed in a quadrant OPBQ. If OA = 15 cm, find the area of the shaded region. (Use π = 3.14)
In Figure, ABCD is a square with side 2√2 cm and inscribed in a circle
In Figure, ABCD is a square with side 2√2 cm and inscribed in a circle. Find the area of the shaded region. (Use π = 3.14)
A solid is in the form of a cylinder with hemispherical ends
A solid is in the form of a cylinder with hemispherical ends. The total height of the solid is 20 cm and the diameter of the cylinder is 7 cm. Find the total volume of the solid. (Use π = 22/7)
Read more …For what value of k, is the polynomial f(x) = 3x^4 – 9x^3 + x^2 + 15x + k
For what value of k, is the polynomial f(x) = 3x4 – 9x3 + x2 + 15x + k completely divisible by 3x2 – 5 ?
Read more …Find the zeroes of the quadratic polynomial 7y^2 – 11y/3 – 2/3
Find the zeroes of the quadratic polynomial 7y2 – 11y/3 – 2/3 and verify the relationship between the zeroes and the coefficients.
Read more …Write all the values of p for which the quadratic equation x^2 + px + 16 = 0
Write all the values of p for which the quadratic equation x2 + px + 16 = 0 has equal roots. Find the roots of the equation so obtained.
Read more …Amit, standing on a horizontal plane, finds a bird flying at a distance of 200 m
Amit, standing on a horizontal plane, finds a bird flying at a distance of 200 m from him at an elevation of 30°. Deepak standing on the roof of a 50 m high building, finds the angle of elevation of the same bird to be 45°. Amit and Deepak are on opposite sides of the bird. Find the distance of the bird from Deepak.
Read more …A solid iron pole consists of a cylinder of height 220 cm and base diameter 24 cm
A solid iron pole consists of a cylinder of height 220 cm and base diameter 24 cm, which is surmounted by another cylinder of height 60 cm and radius 8 cm. Find the mass of the pole, given that 1 cm3 of iron has approximately 8 gm mass. (Use π = 3.14)
Read more …
Which term of the Arithmetic Progression –7, –12, –17, –22
Which term of the Arithmetic Progression –7, –12, –17, –22, ... will be –82 ? Is –100 any term of the A.P. ? Give reason for your answer.
Read more …How many terms of the Arithmetic Progression 45, 39, 33
How many terms of the Arithmetic Progression 45, 39, 33, ... must be taken so that their sum is 180 ? Explain the double answer.
Read more …In a class test, the sum of Arun’s marks in Hindi and English is 30
In a class test, the sum of Arun’s marks in Hindi and English is 30. Had he got 2 marks more in Hindi and 3 marks less in English, the product of the marks would have been 210. Find his marks in the two subjects.
Read more …The absolute refractive index of Ruby is 1.7
The absolute refractive index of Ruby is 1.7. Find the speed of light in Ruby. The speed of light in vacuum is 3 × 108 m/s.
Read more …On heating blue coloured powder of copper (II) nitrate
On heating blue coloured powder of copper (II) nitrate in a boiling tube, black copper oxide, O2 and a brown gas X is formed.
- Identify the type of reaction and the gas X.
- Write balanced chemical equation of the reaction.
- Write the pH range of aqueous solution of the gas X.
While diluting an acid, why is it recommended that the acid
(a) While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid ?
(b) Dry hydrogen chloride gas does not change the colour of dry litmus paper. Why ?
Read more …How is sodium hydroxide manufactured in industries
How is sodium hydroxide manufactured in industries ? Name the process. In this process a gas X is formed as by-product. This gas reacts with lime water to give a compound Y, which is used as a bleaching agent in the chemical industry. Identify X and Y and write the chemical equation of the reactions involved.
Read more …What are amphoteric oxides
What are amphoteric oxides ? Give an example. Write balanced chemical equations to justify your answer.
Read more …What is a homologous series of carbon compounds
What is a homologous series of carbon compounds ? Give an example and list its three characteristics.
Read more …Distinguishing features between autotrophic nutrition and heterotrophic nutrition
List in tabular form three distinguishing features between autotrophic nutrition and heterotrophic nutrition.
Read more …What is translocation
(a) What is translocation ? Why is it essential for plants ?
(b) Where do the substances in plants reach as a result of translocation ?
Read more …What is transpiration? List its two functions
What is transpiration ? List its two functions.
Read more …What is carpel? Write the function of its various parts
What is carpel ? Write the function of its various parts.
Read more …A 10 cm tall object is placed perpendicular to the principal axis
A 10 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 12 cm. The distance of the object from the lens is 18 cm. Find the nature, position and size of the image formed.
Read more …Write the essential function performed by ozone at the higher levels
Write the essential function performed by ozone at the higher levels of the Earth’s atmosphere ? How is it produced ? Name the synthetic chemicals mainly responsible for the drop of amount of ozone in the atmosphere. How can the use of these chemicals be reduced ?
Read more …What are solar cells? Explain the structure of solar panel
What are solar cells ? Explain the structure of solar panel. List two principal advantages associated with solar cells.
Read more …The electrons in the atoms of four elements A, B, C and D
The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons respectively in their outermost shells. Write the group numbers in which these elements are placed in the Modern Periodic Table. Write the electronic configuration of the atoms of B and D and the molecular formula of the compound formed when B and D combine.
Read more …How does the metallic character of elements vary
How does the metallic character of elements vary on moving from
- left to right in a period,
- from top to bottom in a group
of the Modern Periodic Table ? Give reason for your answer.
Read more …List any three observations which posed a challenge to Mendeleev’s Periodic Law
List any three observations which posed a challenge to Mendeleev’s Periodic Law.
Read more …How do nerve impulses travel in the body
How do nerve impulses travel in the body ? Explain.
Read more …Why is the use of iodised salt advisable
Why is the use of iodised salt advisable ? Name the disease caused due to deficiency of iodine in our diet and state its one symptom.
Read more …What is hydrotropism
What is hydrotropism ? Design an experiment to demonstrate this phenomenon.
Read more …Consider the given circuit and find the current flowing
Consider the given circuit and find the current flowing in the circuit and potential difference across the 15 Ω resistor when the circuit is closed.
Calculate the equivalent resistance of the following network
Calculate the equivalent resistance of the following network :
A teacher provided acetic acid, water, lemon juice, aqueous solution
A teacher provided acetic acid, water, lemon juice, aqueous solution of sodium hydrogen carbonate and sodium hydroxide to students in the school laboratory to determine the pH values of these substances using pH papers. One of the students reported the pH values of the given substances as 3, 12, 4, 8 and 14 respectively. Which one of these values is not correct ? Write its correct value stating the reason.
Read more …Placing duly cleaned strips of aluminium, copper, iron and zinc
What would a student report nearly after 30 minutes of placing duly cleaned strips of aluminium, copper, iron and zinc in freshly prepared iron sulphate solution taken in four beakers ?
Read more …What is observed when a pinch of sodium hydrogen carbonate
What is observed when a pinch of sodium hydrogen carbonate is added to 2 mL of acetic acid taken in a test tube ? Write chemical equation for the reaction involved in this case.
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