Journal of the Association of Engineers, India

R. R. Chibba

Abstract

With the growth of industrial civilization the problem of dust has become a serious and alarming issue. The atmosphere that we breathe in is no longer safe and is contaminated with objectionable foreign particles both toxic and nontoxic in nature, depending upon the surroundings.

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R. R. Chibba

Abstract

Out of all the Telephone Systems in the manual working the Central Battery system has proved more efficient and economical.

The current required to energise the subscriber's transmitter, and also for calling and clearing purposes is supplied over the line wires from a set of large accumulators charged by a dynamo at the Exchange.

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