Key Point Paper 2 2020 Flashcards
(13 cards)
How does the atom arrangement change when the object is melting?
Temperature is constant: Change in State
Energy transferred breaks SOME bonds between atoms
What happens to the potential energy and the kinetic energy when the object is melting?
-Kinetic energy stays constant (Kinetic energy is proportional to temperature, and temperature is constant during state changes)
-Potential energy increases.
In the equation Q=mc{change in temp} Do you need to use kelvin or degrees?
Either will do as long as both temperature values are in the same form (degrees-degrees, Kelvin-Kelvin)
What is the equation for Escape velocity?
V^2=2xGxM/r
V-Escape velocity of an object
G-Newtons gravitational constant
M-Mass of the object to be escaped from
r-Distance from the centre of masses
A singly charged lithium ion passes through the small aperture. How would I work out the charge?
1.6x10^19
ITS SINGLY CHARGED
What should you write down when you have a charged particle being accelerated through a potential difference.
eV = 1/2 mv^2
e- electron charge
V- potential difference
m- mass of particle
v- velocity
What does a sinusoidal output on an oscilloscope tell us about the output.
The wave on the oscilloscope is in the shape of a sine wave.
What is the right hand rule?
Thumb - Motion
Index - Field
Middle - Current
Which statement is true about an experiment where Brownian motion is demonstrated using smoke particles in the air?
The motion is caused by collisions between air molecules and smoke particles.
Whch diagram would represent lines of equipotential inn steps of equal potential difference near an isolated point charge.
The diagram with lines surrounding the point which gets further and further away from each other.
When a coil falls down between two magnetic poles where will the flux linkage be the greatest.
At the bottom, coming out of the magnet. This is because speed will continuously increase with acceleration, and then, as a result, the change in flux linkage will also increase the greatest. Therefore, the induced emf will be the greatest.
What is the phase difference between magnetic flux linkage through the coil and the emf? Give the reason.
When magnetic flux density is maximum;
Emf is a minimum;
Therefore, they are 90 degrees out of phase, or pi/2
Lenzs Law
When a current is induced by electromagnetic induction, the direction of the induced emf and current is always such as to oppose the change that causes it.
