The maximum current that flows in the fuse wire, before it blows out, varies with the radius r as

Question

The maximum current that flows in the fuse wire, before it blows out, varies with the radius r as (A)  r3/2  (B) r (C)  r2/3  (D)  r1/2

Tardigrade Admin · Accepted Answer

If I is the safe current through the fuse wire and h is the rate of loss of heat in steady state, I2 R=h A Or I2((ρ L/π r2))=h × 2 π r L Or I propto r3 / 2

Q. The maximum current that flows in the fuse wire, before it blows out, varies with the radius $r$ as

$r^{3/2}$

r

$r^{2/3}$

$r^{1/2}$

If $I$ is the safe current through the fuse wire and $h$ is the rate of loss of heat in steady state,
$I^{2} R = h A$
Or $I^{2} (\frac{ρ L}{π r ^{2}}) = h \times 2 π r L$
Or $I \propto r^{3/2}$

Q. The maximum current that flows in the fuse wire, before it blows out, varies with the radius r as

r3/2

r

r2/3

r1/2

If I is the safe current through the fuse wire and h is the rate of loss of heat in steady state, I2R=hA Or I2(πr2ρL​)=h×2πrL Or I∝r3/2

Q. The maximum current that flows in the fuse wire, before it blows out, varies with the radius $r$ as

$r^{3/2}$

$r^{2/3}$

$r^{1/2}$

If $I$ is the safe current through the fuse wire and $h$ is the rate of loss of heat in steady state,
$I^{2} R = h A$
Or $I^{2} (\frac{ρ L}{π r ^{2}}) = h \times 2 π r L$
Or $I \propto r^{3/2}$