Which of the following are true about electricity and magnetism? i. an electric current can be produced by a changing magnetic force. ii. a magnetic force can be produced by an electric current. iii. energy cannot be transferred by an electric current. iv. a magnetic force can attract a metal object only if the object is touching the magnet.

Answer;

I. An electric current can be produced by a changing magnetic force.

II. A magnetic force can be produced by an electric current.

Explanation;Electric current is the net movement of electric charges in a single direction, measured in amperes (A).Electric current produces a magnetic field. Electric currents and magnets exert force on each other, and this relationship has many uses. A temporary magnet, known as an electromagnet, can be made by passing electric current through a wire that is coiled around an iron core. A magnet can also be used to generate electricity. When a wire moves within a magnet's magnetic field, electricity is produced.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.