Answer:
<em>0.45 mm</em>
Explanation:
The complete question is
a certain fuse "blows" if the current in it exceeds 1.0 A, at which instant the fuse melts with a current density of 620 A/ cm^2. What is the diameter of the wire in the fuse?
A) 0.45 mm
B) 0.63 mm
C.) 0.68 mm
D) 0.91 mm
Current in the fuse is 1.0 A
Current density of the fuse when it melts is 620 A/cm^2
Area of the wire in the fuse = I/ρ
Where I is the current through the fuse
ρ is the current density of the fuse
Area = 1/620 = 1.613 x 10^-3 cm^2
We know that 10000 cm^2 = 1 m^2, therefore,
1.613 x 10^-3 cm^2 = 1.613 x 10^-7 m^2
Recall that this area of this wire is gotten as
A = 
where d is the diameter of the wire
1.613 x 10^-7 = 
6.448 x 10^-7 = 3.142 x 
=
d = 4.5 x 10^-4 m = <em>0.45 mm</em>
we are given in the problem the following dimensions or specifications
B = 0.000055 T r = 0.25 m constant mu0 = 4*pi*10-7
The formula that is applicable from physics is
B = mu0*I/(2*pi*r) I = 2*B*pi*r/mu0 I = 68.75 Amperes
Answer:
B.) to determine that electric beams in cathode ray tubes were actually made of particles
Explanation:
This is the right answer i just took the quiz on edge.
Answer:
Speed of comet before collision is

Explanation:
Correction: (As stated after collision comet moves away from moon so velocity of moon and moon and comet must be opposite in direction. as spped of moon after collision is −4.40 × 10^2km/h so that comet's must be 5.740 × 10^3km/h instead of -5.740 × 10^3km/h)
Solution:

Case is considered as partially inelastic collision, by conservation of momentum

Velocity = fλ
where f is frequency in Hz, and λ is wavelength in meters.
<span>2.04 * 10⁸ m/s = 5.09 * 10¹⁴ Hz * λ </span>
<span>(2.04 * 10⁸ m/s) / (5.09 * 10¹⁴ Hz ) = λ </span>
<span>4.007*10⁻⁷ m = λ </span>
<span>The wavelength of the yellow light = 4.007*10⁻⁷ m<span> </span></span>