Answer:

Explanation:
given,
diameter of the beam (d)= 5.85 cm
= 0.0585 m
average wavelength of the(λ) = 580 n m
angle of of spreading = ?
according to the Rayleigh Criterion the minimum angular spreading, for a circular aperture, is




the minimum angle of spreading is 
Answer:
The frequency of the sound you will hear is 713.85 Hz
Explanation:
Given;
speed of your car,
= 85.0 km/h
frequency of the siren, f = 665 Hz
Speed of sound in air, v = 345 m/s
The frequency of the sound you hear, can be calculated as;

Convert the speed of the car to m/s


Therefore, the frequency of the sound you will hear is 713.85 Hz
Answer:
Number of turns per metre, n= 500/0.3= (5000/3)m^-1
Cross sectional areaof the square loop of wire, A= (0.1^2)m^2= 0.01m^2dB/dt= μn(dI/dt)= (4.00π x10^-7)(5000/3)(0.7)= 1.46608x10^-3T/s
The induced emf in the square loop of wire, ε= the rate of change of magnetic flux of the square loop of wire(dΦ/dt)= A(dB/dt)= (0.01)(1.46608x10^-3)= 0.0146608x10^-5VA
current flows in the square loop of wire since a potential difference(induced emf in this case) exists. Its magnitude,
I= ε/R where R is the resistance of the square loop of wire.
I= (0.0146608x10^-5)/30= 4.89x10^-7A
Answer:
Charge, 
Explanation:
It is given that,
Electric field strength, E = 180000 N/C
Distance from a small object, r = 2.8 cm = 0.028 m
Electric field at a point is given by :

Q is the charge on an object



So, the charge on the object is
. Hence, this is the required solution.
Its been some time so i might be wrong but i think the answer is 3 either or 2