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>
Answer:
The distance and height of the object is 6 m and 2 m.
The image is virtual and upright.
Explanation:
Given that,
Focal length = 0.25 m
Length of image = 0.080 m
Image distance = 0.24 m
We need to calculate the distance of the object
Using formula of lens
Put the value into the formula
We need to calculate the magnification
Using formula of magnification
Put the value into the formula
We need to calculate the height of the object
Using formula of magnification
A convex mirror produce a virtual and upright image behind the mirror.
Hence, The distance and height of the object is 6 m and 2 m.
The image is virtual and upright.
The random variable in this experiment is a Continuous random variable.
Option D
<u>Explanation</u>:
The continuous random variable is random variable where the data can take infinite variables. For example random variable is taken for measuring "speed of automobiles" on the highways. The radar instrument depicts time taken by automobile in particular what speed. They are the generalization of discrete random variables not the real numbers as a random data is created. It gives infinite sets of all possible outcomes. It is obvious that outcomes of the instrument depend on some "physical variables" those are not predictable as depends on the situation.
In light energy, the higher
the frequency, the greater the energy a light contain.
We know for a certain
that frequency is just the reciprocal of wavelength:
frequency = 1 /
wavelength
Calculating for
frequencies:
f UVA = 1/320 to 1/400
f UVA = 0.0031 to 0.0025
f UVB = 1/290 to 1/320
f UVB = 0.0034 to 0.0031
Since UVB has higher frequency range, then it has higher
energy than UVA.
If it's not moving at all at the beginning of the 10 seconds, then it falls 490 meters straight down in 10 seconds.
(Note: This is true of all objects on Earth . . . rubber balls, feathers, grains of sand, school buses, battle ships . . . everything. As long as air doesn't hold them back. Anything falling from rest falls 490 meters in the first 10 seconds.)
