Question

A cylindrical job with diameter of 200 mm and height of 100 mm is to be cast using modulus method of riser design. Assume that the bottom surface of the cylindrical riser does not contribute as the cooking surface. If the diameter of the riser is equal to is height, then the height of the riser (in mm) is

• A. 150
• B. 100
• C. 200
• D. 125

Answer 1

The correct option is A 150

$\text{According to modulus method}$

$M_R=1.2M_C$

$M_R={\left(\frac{V}{A}\right)}_R=\left[\frac{\frac{\pi }{4}{d}^{2}h}{\frac{\pi }{4}{d}^2+\pi dh}\right]$

$\text{If h = d}$

$M_R=\frac{d}{6}$

$\text{Now,}{M}_R=1.2M_C$

$\frac{d}{6}=1.2\times \left[\frac{\frac{\pi }{4}\times {200}^2\times 100}{2\times \frac{\pi }{4}\times {200}^2+\pi \times 200\times 100}\right]$

$\text{d = 6×25 = 150 mm}$

$\because \text{For riser, d = h = 150 mm}$