Test 4 (completed) Flashcards
Define pressure
the force acting per unit area at right angles to a surface
Pressure increases with depth. What about with density?
Increases
A student carries out an experiment to determine the specific heat capacity of a metal. A cylinder of the metal is heated by a 12W electrical heater.
State the readings that the student takes.
time, mass, initial and final temperature
State the name for the defect of vision that can be corrected by a converging lens.
Long-sightedness
State the name for the defect of vision that can be corrected by a diverging lens.
Short-sightedness
Describe how a converging lens corrects long-sightedness.
You may find it helpful to sketch a ray diagram.
Without lens, rays converge behind of back of the eye. With, rays converge at the back of the eye.
State the type of electromagnetic radiation, other than visible light, which is used in glass optical fibres.
Infrared
Give two reasons why these two types of electromagnetic radiation are used in glass optical fibres for high-speed broadband.
Glass is transparent to visible light and some infrared. Can carry high rates of data.
An electric heater uses a resistance wire of resistance 26Ω. The power dissipated in the resistance
wire is 2500W. Calculate the current in the resistance wire.
P=I^2R
The resistance wire of the heater has a length of 1.2m and a cross-sectional area of
7.9 × 10–7m2.
A new heater is designed using wire of the same material with length 1.8m and cross-
sectional area 5.8 × 10–7m2.
Calculate the resistance of this wire.
R=L/A
First one on top.
What to remember with triangle diagrams?
head to tail
river current and bank
What to remember with Fleming’s left and right hand rules
field
During β-decay, one of the neutrons in the nucleus changes. Explain how charge is conserved during this change.
charge on neutron = 0 OR total charge on products = 0
charge on proton = +1 AND charge on electron =
–1
(Planets)
Greater field=
larger mass and less dense
