Rectilinear propagation/light travels in a straight line;√

To concentrate the magnetic field.

(a) A- Zinc√

B-Copper√

(b) Because of increased resistance caused by polarization / local action

-More information can be transmitted at the same time/ no loss of energy during transmission

The object attracted then repelled. √

In B more current due to lower / reduced effective resistance or in A less current flows due higher effective resistance √

(b) Soft magnetic material is easily magnetized and demagnetized while a hard magnetic material is difficult to magnetize and demagnetize.√1

(a) Like poles repel, unlike poles attract.√

(b) A-North.√ B-North√

(c) (i)

(iii) -number of turns.√ -magnitude of current

-bring a negatively charged strip near the cap of the electroscope

-Touch the cap of the electroscope momentarily/ earth the cap

-Remove the finger with the strip near the cap;/ disconnect the earthing -Remove the rod

Location of F .√
Correct rays.√
Image position.√

(c) (i) -light must travel from an optically denser medium to optically less dense medium;

-the angle of incidence must be greater than the critical angle;

(a) Current flowing through a conductor is directly proportional to the p.d across the conductor provide a temperature and other physical conditions are kept constant. (b)

(a) (i) Diffraction –spreading of waves beyond openings/obstacles. 1mark

Refraction –is the bending of waves when they change medium.

(ii) change in velocity

(b) (i) Constant loud sound√1; due to constructive interference√1

(ii) The soft sound is due to destructive interference√1when a rarefaction merge with a compression; the loud is due to constructive interference√1 of compressions/rarefactions;

(c) - same wavelength

-same frequency

-same/nearly same amplitude