The answer is A. Proton. Protons have the opposite charge to electrons, which have negative charges.
The bar magnet and the electromagnet act identical. The difference being a electromagnet is a coil of wire that has a power source connect to both ends, this energizes the coil with an electromagnetic field.
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.
300/8 = 37.5
37.5 x 12 = 450
New temp. = 450 K
Hope this helps!
