Doubtly
@Doubtly · Joined Feb 2021
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- A cylinder and a cone have equal bases. The height of the cylinder is 3 cm and the area of its base is 100 cm2 . Height of the cylinder, h = 3 cm Let the radius of the cylinder be r cm and the height of the cone be H cm. Area of the base of cylinder = 1... 1
- Observe the measures of pots in figure 7.8 and 7.9. How many jugs of water can the cylindrical pot hold ? Given: For the conical water jug, radius (r) = 3.5 cm, height (h) = 10 cm For the cylindrical water pot, radius (R) = 7 cm, height (H) = 10... 2
- The dimensions of a cuboid are 44 cm, 21 cm, 12 cm. It is melted and a cone of height 24 cm is made. Find the radius of its base Radius is 21 cm 1
- Find the surface area of a sphere of radius 7 cm. Answer is 616 sq. cm 2
- Find the total surface area of a cylinder if the radius of its base is 5 cm and height is 40 cm. Given :: radius of base of cylinder= 5 cm height = 40 cm for cylinder , Total surface area of cylinder = 2π r (r+h) =2x3.14x5x(5+40) =2x3.14... 1
- Find the volume of a sphere of diameter 6 cm For the sphere , diameter d=6 cm radius r= diameter/2 = 6/2 =3 Volume of sphere = 4/3π r³ = 4/33.14 x 3³ =113.04 cm³ 1
- Find the volume of a cone if the radius of its base is 1.5 cm and its perpendicular height is 5 cm. The correct Answer is 11.79 cm³ =11.79 cm³ 1
- A student uses her thumb to push a drawing pin (thumb tack) into a notice board. The pin goes into the board but does not penetrate her thumb. Answer: (D) The pressure of the pin on the notice board is greater than the pressure of the pin on her thumb. The force transmitted through... 1
- A man climbs a ladder. Which quantities can be used to calculate the useful power of the man? Answer: (C) the work done by the man and the time taken only Power is the rate of doing work: P = work done/time taken So the useful power n... 1
- Which source of energy is renewable? A coal B natural gas C oil D wind Answer: (D) wind A renewable source of energy is one that is replenished naturally and will not run out. Wind is produced continuously by th... 1
- Shantikunj is a thickly populated locality inhabited mainly by the working-class people. Unfortunately, there is no Mother 4 Shantikunj Delhi (Date) To, The Editor The New Indian Express Delhi Subject: Request for a Mother Dairy Milk BoothSir, Shantikunj is a ver... 1
- Accidents in big cities is a common phenomenon. Unfortunately, hardly anyone comes to the rescue of road victims because of fear of harassment by the police. 24, Raj Nagar Kanpur Uttar Pradesh (Date) The Editor National daily Kanpur Subject: To make people aware of Supreme Court guidelines sir , A... 1
- You are John/Jennifer, the incharge of tour and excursion club of Grand Public School, Agra. During the summer break, you are planning replace name with {John/Jennifer} [Your Name] Your Address City, State Date To, India Travel and Tour Agency Address City, State Pin Code De... 1
- You are Somita Roy, the librarian of ABC Public School, New Delhi. Write a letter to the Unique Book Co., New Delhi, complaining about the poor ABC Public School New Delhi Date: [insert date] To, Unique Book Co. [insert address] New Delhi Subject: Complaint about poor quality of book... 1
- You are Mr. Malik, the coordinator of the ABC Public School. Write a letter to place a bulk order for school uniform to M/S Sinha Garments. ABC Public School [insert address] [insert city, state, zip code] Date: [insert date] To, M/S Sinha Garments [insert address] [insert city,... 1
- Many complaints about unfair means being used in exams have been reported. Write a letter to the Editor 12 Fort Road, Kochi, May 10, 2023 The Editor, The National Daily, New Delhi Subject: Unfair Means in Exams Dear Sir/Madam, I am writing to e... 1
- The influence of friends can have both positive and negative impact on the students. Write a letter Formal letter to the editor on making peer influence positive. 24, Mall Road Chennai [Date] The Editor The Hindu Chennai Subject: Making pee... 1
- Our metropolitan cities witness a large number of accidents every day , Write a letter Formal letter to the editor about road accidents in metropolitan cities. 112, Model Town Delhi [Date] The Editor The Hindustan Times New Del... 1