Question

A current of 2 A flows in conductors as shown. The potential difference V_A- V_B will be ________.

Options

• - 1 V

• + 1 V

• + 2 V

• + 4 V

Answer 1

A current of 2 A flows in conductors as shown. The potential difference V_A- V_B will be + 1 V.

Explanation:

Potential divider formula,

`"V"_"X" = "R"_"X"/"R"_"arm" xx "V"_"arm"`

R_X is resistance across which potential drop is to be determined,

R_arm is resistance of arm and V_arm is potential across arm.

`"V"_"s" = "I" xx "R"_"total" = 2 xx 5/2` = 5V

`"V"_"CA" = "R"_"A"/"R"_"CD" xx "V"_"s"`

`=> "V"_"CA" = 2/5 xx 5` = 2V

and "V"_"CB" = 3/5 xx 5` = 3V

potential at A, V_A = 5 - 2 = 3V

potential at B, V_B = 5 - 3 = 2V , hence potential difference is given by ;

∴ V_A - V_B = 3 - 2 = 1 V