Lesson 53. A Glimpse of Vyanjana Sandhi.
When consonants join the joining bandwagon, we get, what you call, Vyanjana Sandhi..... व्यञ्जन-सन्धिः।  One of the most frequently used sandhi is the जश्त्व-सन्धिः, We can do the rest of the व्यञ्जन-सन्धिः at a later date.
जश्त्व-सन्धिः (1 ) Go by these rules:
If a word ends with the first व्यञ्जन of the five वर्ग s  ( that is : either  क् , च् , ट्, त् or  प्   ) and is then followed by a word beginning with any swara then that व्यञ्जन of the first word gets transformed into the third व्यञ्जन of the same वर्ग .

That is :
क् + any swara becomes ग्      
च्  + any swara becomes ज्     
ट् + any swara becomes ड्        
त् + any swara becomes द्         
प् + any swara becomes ब्        
Then it gets added to the swara of the next word again to form a new letter.
                                                                      Try the exercises in 53 A. in Lesson 53 A

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