YASH CLASSES
5.ELECTRIC CURRENT
47. What is resistance ? what factor are
affecting the
resistance .
48. What is resistivity
of conductor .Write
its S.I.
units .
49. Difference between
electric resistance and
resistivity .
50. Why are coils of toasters and electric iron are
made
of alloy instead
pure metal ?
51. Which metal is
lowest resistivity ?
52. Resistance of wire is 26Ω at 20℃ and
its
length 1 m. if the diameter of wire is 0.3 mm,
what
will be the resistivity of the
metal wire
at that
temperature ?
53. Resistance of
wire is 20Ω
at 20℃
and its
length 1 m. if the diameter of wire is 0.5 mm,
what
will be the resistivity of the
metal wire
at that
temperature ?
54. Resistance of wire
is 10Ω at 20℃
and its
length 1 m. if the diameter of wire is 1.5 mm,
what
will be the resistivity of the
metal wire
at that
temperature ?
55. Resistance
of wire is 18Ω at 20℃
and its
length 1 m. if the diameter of wire is 2 mm,
what
will be the resistivity of the
metal wire
at
that temperature ?