If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

A wire when connected to $$220$$ $$V$$ mains supply has power dissipation $${P_1}.$$ Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is $${P_2}.$$ Then $${P_2}:{P_1}$$ is

If in the circuit, power dissipation is $$150W,$$ then $$R$$ is

If a current is passed through a spring then the spring will