14) C, it cant be A because it’s a young child and therefore wont be stationary for 10 minutes, cannot be D because it cannot produce images of dense tissue, it cant be B because the penetration depth is only 1 cm
16) D, it cant be A or C because it consists of air, and the optical fibres are only made of glass, its D because the high refractive glass index would be on the inside to allow for the total internal reflection. The low refractive index glass wouldn’t allow for this
17) A, you have to think logically about this, it cannot be B or D because the ball will not move (not allowing the blood to pass through) and it cannot be C because it wont allow for the blood to pass through.
19) D, its obviously not A or B because the investigation isn’t valid. It is D because as stat dint he question, the thermometer reads 15 degrees in an 18 degree room with 3 degrees stuck at the top. Therefore to allow for the correct reading, person needs to add 3 degrees to the temperature observed to get the correct reading
20) I got C, but not definite. You have to remember that the electronic device is turned off when the tapping key is released, therefore it cannot be A or B as it doesn’t represent the turning off at all, and its not D because I think that represents Binary codes or something. C shows the sound and also how there is nothing produced when the key is released.
I did the exam this year so not definite on the answers but i hope i helped
