i] Heating elements of electrical heating devices is made up of an alloy rather than a pure metal. Give two reasons. ii] Four resistors of 2Omega each are joined end to end to form a square. Calculate the equivalent resistance of the combination between two adjacent corners?

i] Heating elements of electrical heating devices is made up of an all

1.	i] Heating elements of electrical heating devices is made up of an alloy rather than a pure metal. Give two reasons. ii] Four resistors of 2Omega each are joined end to end to form a square. Calculate the equivalent resistance of the combination between two adjacent corners?
Answer» SOLUTION :i] Heating elements of electrical heating devices are made up of an alloy rather than a pure metal because a] The resistivity of an alloy is more than the resistivity of a pure metal. b] Alloy does not burn [or oxidize] easily even at higher temperature. II] Resistors, `R_(1),R_(2)andR_(3)` are in series, THEREFORE their equivalent resistance is `R_(s)=R_(1)+R_(2)+R_(3)=2+2+2=6`ohm Now, `R_(s)andR_(4)` are in parallel, therefore equivalent resistance of the combination between two ADJACENT corners A and D is `1/R_(p)=1/R_(s)+1/R_(4)=1/6+1/2=2/3` Therefore, `R_(p)=1.5` ohm