In the figure shown if we connect a source of 2 v with internal resistance of1 Ω at a b with positive terminal at a , then current through r is...

 

In the figure shown if we connect a source of 2 v with internal resistance of1 Ω at a b with positive terminal at a , then current through r is...

First you need to tell us what you've done already. We (and I think it's safe to speak for everyone) will not just hand you the answers--expect us to make you work for it

Now, as you were probably taught in class, a current source in parallel with a resistor is equivalent to a voltage source in series with the same resistor. I suggest you replace the current source/parallel resistor with a voltage source/resistor, and things might start looking familiar. You'll need to find the total resistance, and use the voltage you calculate for the source to determine the current at any given point in the circuit.

Regards,
Matt