Which of the following particles is not a candidate for dark matter?

higgs boson

neutrino

axion

neutralino

Acharged particle moves in a circular path in a uniform magnetic field.which of the following would increase the period of the particle's motion? check all that apply.increasing its chargeincreasing its massincreasing the field strengthincreasing its speed

Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 15°c. (b) what is the temperature at the center of cylinder a?

What causes an electric current in a wire?