Question:
The frequency of pulsing in a die-sinking electric discharge machine (EDM) is 10 kHz. The pulse off-time is set at 40 micro-seconds. The duty factor at this setting is
The frequency of pulsing in a die-sinking electric discharge machine (EDM) is 10 kHz. The pulse off-time is set at 40 micro-seconds. The duty factor at this setting is
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In EDM, the duty factor is the ratio of the pulse on-time to the total cycle time. It determines the efficiency of the process.
Updated On: Dec 26, 2025
- 0.40
- 0.60
- 0.67
- 2.50
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The Correct Option is B
Solution and Explanation
The duty factor in an EDM machine is the ratio of pulse on-time to the total pulse period. The formula for duty factor is:
\[
\text{Duty Factor} = \frac{\text{Pulse On-Time}}{\text{Pulse Period}} = \frac{\text{Pulse On-Time}}{\frac{1}{\text{Frequency}}}
\]
Given:
- Frequency \( f = 10 \text{ kHz} = 10,000 \text{ Hz} \)
- Pulse Off-Time \( t_{\text{off}} = 40 \, \mu\text{s} = 40 \times 10^{-6} \text{ seconds} \)
The pulse period is the total time for one cycle, which is the inverse of the frequency: \[ \text{Pulse Period} = \frac{1}{f} = \frac{1}{10,000} = 0.0001 \text{ seconds} \] Now, the pulse on-time is the total cycle time minus the off-time: \[ \text{Pulse On-Time} = \text{Pulse Period} - \text{Pulse Off-Time} = 0.0001 - 40 \times 10^{-6} = 0.00006 \text{ seconds} \] Now, calculating the duty factor: \[ \text{Duty Factor} = \frac{0.00006}{0.0001} = 0.6 \] Thus, the correct answer is (B) 0.60.
- Frequency \( f = 10 \text{ kHz} = 10,000 \text{ Hz} \)
- Pulse Off-Time \( t_{\text{off}} = 40 \, \mu\text{s} = 40 \times 10^{-6} \text{ seconds} \)
The pulse period is the total time for one cycle, which is the inverse of the frequency: \[ \text{Pulse Period} = \frac{1}{f} = \frac{1}{10,000} = 0.0001 \text{ seconds} \] Now, the pulse on-time is the total cycle time minus the off-time: \[ \text{Pulse On-Time} = \text{Pulse Period} - \text{Pulse Off-Time} = 0.0001 - 40 \times 10^{-6} = 0.00006 \text{ seconds} \] Now, calculating the duty factor: \[ \text{Duty Factor} = \frac{0.00006}{0.0001} = 0.6 \] Thus, the correct answer is (B) 0.60.
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