Which statement about electric and magnetic fields is true

a. electric fields must leave a positive charge and end on a negative charge

b. electric fields and magnetic fields start at a positive and end at a negative.

c. magnetic fields must start at the north pole of a magnet and end at the south pole of a magnet.

d. electric fields loop from south to north

Selma made a diagram to compare convection and radiation. which label belongs in the area marked x? must involve temperature differences between substances or objects only occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter

An engine undergoes a cycle as shown in the diagram. during a complete cycle the work done by the gas is 28.5×103 j and the energy transferred thermally out is 99.4×103 j. there are 1.5×1024 gas molecules and they have three active degrees of freedom. 6. (6 pts) during which process(es) is energy transferred thermally into the gas? a. 1→2 b. 2→3 c. 4→1 d. 1→2 and 4→1 e. none of the above

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2