Answer:
Frequency = 
Wavenumber = 
Energy = 
Energy = 1.4579 eV
Energy = 
Explanation:
As we are given the wavelength = 850 nm
conversion used : 
So, wavelength is 
The relation between frequency and wavelength is shown below as:

Where, c is the speed of light having value = 
So, Frequency is:


Wavenumber is the reciprocal of wavelength.
So,


Also,

where, h is Plank's constant having value as 
So,


Also,

So,


Also,

So,


Answer:
the required diameter of the rod is 9.77 mm
Explanation:
Given:
Length = 1.5 m
Tension(P) = 3 kN = 3 × 10³ N
Maximum allowable stress(S) = 40 MPa = 40 × 10⁶ Pa
E = 70 GPa = 70 × 10⁹ Pa
δ = 1 mm = 1 × 10⁻³ m
The required diameter(d) = ?
a) for stress
The stress equation is given by:
A is the area = πd²/4 = (3.14 × d²)/4





Substituting the values, we get



d = (9.77 × 10⁻³) m
d = 9.77 mm
b) for deformation
δ = (P×L) / (A×E)
A = (P×L) / (E×δ) = (3000 × 1.5) / (1 × 10⁻³ × 70 × 10⁹) = 0.000063
d² = (4 × A) / π = (0.000063 × 4) / 3.14
d² = 0.0000819
d = 9.05 × 10⁻³ m = 9.05 mm
We use the larger value of diameter = 9.77 mm
Probably because it’s metal and metal is a better thermal conductor
Answer:
The given blanks can be filled as given below
Voltmeter must be connected in parallel
Explanation:
A voltmeter is connected in parallel to measure the voltage drop across a resistor this is because in parallel connection, current is divided in each parallel branch and voltage remains same in parallel connections.
Therefore, in order to measure the same voltage across the voltmeter as that of the voltage drop across resistor, voltmeter must be connected in parallel.