Question 421: Current Electricity

Question

In the following circuit, the magnitude of current I1, is ___________ A.

Accepted Answer

The indicated diagram shows current flow diagram loops for writing Kirchhoff's law are also indicated, writing the equation
$$2{I_3} + {I_1} + {I_3} + {I_2} = 5$$
or $${I_1} + {I_2} + 3{I_3} = 5$$ ..... (1)
$${I_2} - 5 = 2({I_3} - {I_2}) + ({I_1} + {I_3} - {I_2})$$
or $${I_1} - 4{I_2} + 3{I_3} =  - 5$$ ...... (2)
$$({I_1} + {I_3}) + ({I_1} + {I_3} - {I_2}) = 2$$
or $$2{I_1} - {I_2} + 2{I_3} = 2$$ ...... (3)
on solving $${I_1} = {3 \over 2}A,{I_2} = 2,{I_3} = {1 \over 2}A$$
$$ = 1.50$$

Current Electricity

In the following circuit, the magnitude of current I1, is ___________ A.

Choose the correct answer: