नील मेघ

A better device is the triac, bidirectional thyristor, which allows the full a.c. power to be controlled. It comprises two thyristors connected in parallel and working in opposition but controlled by the same gate. The trigger pulses to a triac are provided by a special device called diac, bidirectional breakdown diode. It is, in effect, two Zener diodes connected back to back. The diac conducts in either direction if the applied voltage reaches the breakdown voltage of about 30 V. This

Aloe vera is India’s most favorite herbal medicinal plant that is require low maintenance and easy to grow. The name of aloe is derived from Arabic word “Alloeh” meaning a shining bitter substance. Aloe vera belongs to the family Asphodelaceae (liliaceae) (Ghazanfar, 1994). It grows mainly in the dry regions of Africa, Asia, Europe and America. In India, it is found in Rajasthan, Andhra Pradesh, Gujrat, Maharashtra, and Tamil Nadu. Aloe vera is popular in Ayurvedic medicine (Richard, 2005). There are more than 300 species of aloe plants. This plant has yellow flower the leaves are arranged in rosette configuration. They are triangular and spear like and have thorny ridges. Aloe vera is a customary, dry spell dispute, sticky plant.

Dear Students at this level are supposed to have some fundamental knowledge of English grammar. This book helps students to improve their grammar knowledge, expanding their vocabulary, and becoming more confident in following expressing themselves in English.