(i) State Joule's law off heating.
(ii) An alloy of nickel and chromium is used as the heating element. Why?
(iii) How does a fuse wire protect electrical appliances?

(a) State Joule's law of heating. (b) an alloy of nickel and chromium is used as the heating element. Why ? (c ) How does a fuse wire protect electrical appliances ?

Why nickel is used as heating element ?

(i) Define electric potential and potential difference. (ii) How does a fuse wire protect electrical appliances?

When the magnetic flux associated with a coil changes an emf is induced in the circuit. A. State Faraday's law of electromagnetic induction. B. Mention the physical significance of Len'z law with an example. C. When an electrical appliance is switched off, sparking occurs. Why?

Electric field lines are a pictorial representation of the electric field around charges. A. State Gauss's Law in Electrostatics. B. Using this law derive an expression for the electric field intensity due to a uniformly charged thin spherical shell at a point. i. Outside the shell ii. Inside the shell C. Suppose that you are in a cave deep withing the earth. Are you safe from thunder and lighting? Why?

a. Magnetic field lines show the direction (at every point) along which a small magnetised needle aligns (at the point) Do the magnetic field also represent the lines of force one a moving charged particle at every point ? b. Magnetic field lines can be entirely confined within the core of a toroid , but not within a straight solenoid. Why ? c. If magnetic monopoles existed, how would the Gauss ' law of magnetism be modified ? d. Does a bar magnet exert a torque on itself due to its own field ? Does one element of a current - carrying wire exert a force on another element of the same wire ? e.Magnetic field arises due to charges in motion . Can a system have magnetic moments eventhough its charge is zero ?