Suggest good books for Competitive electrical exams

Hi Friends,
I'm an electrical engineering graduate, planning to prepare for various Competitive electrical exams like NTPC, BHEL,NHPC, A.P.TRNSCO, A.P.GENCO, APCPDCL, etc...
I'm looking for a good book(good author) which can assist me with the following features:

1. Objective Questions (Solved Questions).
2. Should be able to provide quick short cut tips to analyse the given problem.
(I say - short cut tips because time factor plays major role).

Please reply to me with you suggestions.

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