Select the rpm of a high speed drill of Φ20 mm to drill a plate of Mild Steel with a recommended cutting speed of 31.4 meter/minute  

This question was previously asked in
ISRO VSSC Technician-B (Fitter) Official Paper (Held On: 14 July 2021)
View all ISRO Technician B Fitter Papers >
  1. 628 rpm
  2. 500 rpm
  3. 1000 rpm
  4. 1256 rpm

Answer (Detailed Solution Below)

Option 2 : 500 rpm
Free
ISRO Technician B: Fitter Full Test 1
16.8 K Users
60 Questions 180 Marks 90 Mins

Detailed Solution

Download Solution PDF

Concept:

Speed of the cutting tool is given by:

V = \(\frac{\pi~\times~D~\times~N}{1000}\)

V = Cutting speed (m/min), D = Diameter of drill, N = RPM

Calculation:

Given:

D = 20 mm, V = 31.4 m/min

∵ V = \(\frac{\pi~\times~D~\times~N}{1000}\)

⇒ 31.4 = \(\frac{\pi~\times~20~\times~N}{1000}\)

⇒ N = 500 rpm

Latest ISRO Technician B Fitter Updates

Last updated on May 28, 2025

-> ISRO Technician Fitter recruitment notification 2025 has been released

->Candidates can fill ISRO Fitter application form from June 2 to 16. 

->A total of 20 vacancies are announced for ISRO recruitment 2025 for Fitter.

->Candidates must have passed SSLC/ SSC/ Matriculation and should have NTC/ITI/NAC in ->Fitter Trade Certificate from an NCVT recognized by the government to satisfy the ISRO Technician B Fitter Eligibility Criteria.

Get Free Access Now
Hot Links: teen patti master apk teen patti joy official teen patti real cash