Why did the British defeat the Nawab of Bengal in the Battle of plassey?

Causes of the defeat of Siraj ud Daulah

• He was not a much loved ruler
•  Ghaseti Begum (Meherun-Nisa),  and another nephew, Shawkat Jang, wanted to remove Siraj from the throne
• Mir Jafar, commander-in-chief of the army  was courted assiduously by Ghaseti
• Mir Jafar and Aminchand collaborated with teh British against Siraj
• Siraj's army did not raise arms aginst teh British in the war field.