Question

The solidification of a casting starts at 10 AM. However, the solidification of the molten metal at the center-line of the mold starts at 10:03 AM and ends at 10:10 AM. The casting is considered solidified completely when the solidification is completed at the center-line of the mold. The center-line feeding resistance (CFR) in percentage is .............

Hint:

The center-line feeding resistance (CFR) indicates how efficiently the solidification progresses at the center-line of the mold. A higher CFR suggests slower solidification at the center.

Answer 1

Correct Answer: 70

The center-line feeding resistance (CFR) is a measure of how solidification at the center-line of a mold affects the overall process. To calculate CFR, we use the formula:

CFR (%) = (Solidification time at center-line / Total solidification time) × 100

Given:
- Solidification at center-line starts at: 10:03 AM
- Ends at: 10:10 AM
- Total solidification time (complete): Starts at 10:00 AM and ends at 10:10 AM.

First, calculate the solidification time at the center-line:
Start Time: 10:03 AM, End Time: 10:10 AM
Duration = 10:10 AM - 10:03 AM = 7 minutes.

Next, calculate the total solidification time:
Start Time: 10:00 AM, End Time: 10:10 AM
Duration = 10:10 AM - 10:00 AM = 10 minutes.

Now, substitute these values into the CFR formula:

CFR (%) = (7 minutes / 10 minutes) × 100 = 70%

The CFR is 70% which indeed falls within the given range of 70 to 70. Therefore, the calculation is accurate and confirmed.