-- A shorter wire will allow electricity to move through at a higher rate than a longer wire . . . True, but "rate" is a poor way to say it. It should say "a higher current".

-- A short, thick, cold wire is the best conductor . . . True

-- How well a material conducts current is an internal factor affecting resistance . . . True

-- If you double the length of a wire, you cut the resistance in half . . . False. Double the length also means double the resistance.

-- If you double the thickness of a wire, you cut the resistance in half . . . True

-- Superconductors have no measurable resistance . . . True. They literally have NO resistance.

-- The higher the temperature of the conductor, the lower the resistance . . . False. Higher temperature means higher resistance, for almost all conductors.

-- The resistance in a wire with less thickness is less . . . False. We just said, up above in Question-#5, "If you double the thickness of a wire, you cut the resistance in half". Less thickness means more resistance. Just like a highway with fewer lanes.

-- Thickness, length, and temperature are internal factors that affect resistance . . . False. They affect resistance, but they're external factors.

-- When a light is first switched on the light bulb's filament has a lower resistance than after it gives off light for awhile . . . True. Look back 3 questions from here, where it says "Higher temperature means higher resistance".

3 0

3 years ago

Can someone help?

laila [671]

Answer:

i) 21 cm

ii) At infinity behind the lens.

iii) A virtual, upright, enlarged image behind the object

Explanation:

First identify,

object distance (u) = 42 cm (distance between object and lens, 50 cm - 8 cm)

image distance (v) = 42 cm (distance between image and lens, 92 cm - 50 cm)