In ohmic law the voltage is directly proportional to current while in case of electric transformer the situation is quite reverse voltage is inversely proportion to current.clarification is required.

Actually, according to Ohm,s Law I= V/R, clearly Current is directly proportional to the Voltage, But according to P=VI or I=P/V, it shows that current is inversely proportional to the Voltage.

It depends on how you increase the voltage if you increase it by keeping the power of the source constant or not,if the power of the source is constant then the current would decrease when voltage increasing ....if you don't care about the power and just simply replace the battery with a new one's with higher power rating this can increase the current.

In Transformer, when voltage increases then current decrease because power remains constant...both side power is P=VI

By Ohm's Law, Current (I) is directly proportional to the Voltage (V) if Resistance (R) and Temperature remain same.
I = V/R.....or...R=V/I.....or......V=IR.

According to P=VI...or...I=P/V....or ...V=P/I,..... It says that Current inversely proportional to the voltage if power remain same.As we know that in Transformer, If power remain same, and voltage increase, then current decreases in Step Up Transformer. also Voltage decreases when current increases as in Step Down Transformer.