these resistors are usually of carbon composition

Question

These resistors are usually of carbon composition, carbon film on a ceramic rod and sealed in evacuated glass tube. End connections are made up of copper clad nickel-iron alloy.

SPECIFICATIONS

Range of values                                                                    10⁷ to 10¹³ ohms

Temperature coefficient                                                          0.05 to 0.25%/⁰C

APPLICATIONS: These are useful in measuring instruments for atomic energy where small currents are to be detected.