All Exams Test series for 1 year @ ₹349 only
Question

The surface area (in cm²) of a sphere of radius 14 cm is: Take π = 22/7

The correct answer is
2464

Understanding Sphere Surface Area Calculation

The question asks for the surface area of a sphere given its radius and the value of π.

Given Information:

  • Radius of the sphere, $r = 14$ cm
  • Value of π, $ \pi = \frac{22}{7} $

Formula Needed:

The formula for the surface area (A) of a sphere is:

$$A = 4 \pi r^2$$

Step-by-Step Calculation

  1. Substitute the given values into the formula:

    $$A = 4 \times \frac{22}{7} \times (14 \text{ cm})^2$$

  2. Expand the radius squared term:

    $$A = 4 \times \frac{22}{7} \times (14 \text{ cm} \times 14 \text{ cm})$$

  3. Simplify the expression by canceling out the common factor of 7:

    $$A = 4 \times 22 \times \left(\frac{14}{7}\right) \times 14 \text{ cm}^2$$

    $$A = 4 \times 22 \times 2 \times 14 \text{ cm}^2$$

  4. Perform the multiplication:

    First, multiply 4 by 22:

    $$4 \times 22 = 88$$

    Then, multiply the result by 2:

    $$88 \times 2 = 176$$

    Finally, multiply this by 14:

    $$176 \times 14$$

    To calculate $176 \times 14$:

    $$176 \times 10 = 1760$$

    $$176 \times 4 = 704$$

    $$1760 + 704 = 2464$$

    Therefore, the surface area is:

    $$A = 2464 \text{ cm}^2$$

Result Verification

The calculated surface area is 2464 cm². This matches option 4.

Was this answer helpful?

Important Questions from Mensuration

  1. In a circular garden of radius 15 m, a path of 2 m wide has to be made inside the garden at the rate of ₹ 24 per sq. m. The cost of making the path is: (Take π = \(\frac{22}{7}\) )

  2. A hollow cylinder with outer radius 4 cm and height 2 cm is made up of 1 cm thick metal sheet. What is the volume of metal used? (Take π = \(\frac{22}{7}\))

  3. The length and breadth of a rectangular field are in the ratio 4 : 3. If the cost of cultivating the field at 2 per m 2is 600, then the length of the field is:

  4. A cylindrical tank has a capacity of 5632 m3. If the diameter of its base is 8 m, what is the depth of the cylindrical tank? (Use π = \(\frac{22}{7}\))

  5. Find the surface area of a sphere whose diameter is equal to 28 cm.

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App