Answer:
Explanation:
Given a material with temperature coefficient of resistance <em>c</em>, the equation that relates the resistance at temperature
and the resistance
at temperature
is
We want to double our resistance, so , thus having:
For this T must be:
which for our values means (with , remember to write temperature in S.I., and that for silver
):
Answer:
E=1824.81 V/m
Explanation:
Given that
Voltage difference = 5 V
Distance ,D= 3 mm
θ = 24°
As we know that electric filed given as
Given that D is 24° with respect to the perpendicular to the electrodes.So we have to take cos component of D.
d= D cosθ
d= 3 cos24°
d = 2.74 mm
So
E=1824.81 V/m
Answer:
the number of grains in the ball is 274,848
Explanation:
Given that;
diameter = 0.5 mm
so radius r = 0.25 mm
first we determine the volume of the ball using the following equation;
V = 4/3×πr³
we substitute
V = 4/3×π(0.25)³
V = 0.06544 mm³
Now form table 1.1 "Grain sizes" a metal with grain size number of 12 has about 4,200,000 grains/mm³
so;
Number of grains N = 0.06544 × 4,200,000
N = 274,848 grains
Therefore, the number of grains in the ball is 274,848
