So we want to know how can we detect infrared rays without an instrument. Infrared rays or heat, are a part of electromagnetic spectrum. We have specialized nerve cells in our skin called thermoreceptors that can detect differences in temperature that are produced by infrared part of EM spectrum.
Answer:

Explanation:
Given that
Length= 2L
Linear charge density=λ
Distance= d
K=1/(4πε)
The electric field at point P



So

Now by integrating above equation

Answer:
load (l)=400N
Effort(E)=50N
mechanical advantage (MA)= load ÷Effort
(ma)=400÷50
(ma)=8
Explanation:
I copy pasted from the answer from the same question. Remember to first check if ur question is there
Answer: B
It can exist in many alloys, usually with a carbon base
Explanation:
Iron forms many alloys with a carbon base. Steel is an alloy of iron and carbon. There are many different types of steel needed for different applications. Various metals are added to tune the steel to the required properties. For instance, stainless steel contains 10-30% chromium in addition to iron and a low percentage of carbon. Steel remains an extremely versatile alloy used for many different purposes.