Kirchhoff's first rule $$\Sigma$$I = 0 and second rule $$\Sigma$$IR = $$\Sigma$$E (where the symbols have their usual meanings) are respectively based on -

The electric power consumed by a 220 V $$-$$ 100 W bulb when operated at 110 V is

Which of the following has negative temperature coefficient of resistivity?

Two wires carrying currents I₁ and I₂ lie, one slightly above the other, in a horizontal plane as shown in figure. The region of vertically upward strongest magnetic field is