Physics
Solar power:
two advantages from: no polluting gases /quiet/low maintenance / can be placed on roofs /
clean/ cheap to run B2 two disadvantages from: intermittent supply / unattractive / takes up
space/ uses land /d.c. output
Internatl energy-sum of total kinetic energy and potential energy of all molecules
How temp changes whil transferring energy to surrounding?
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Optical fibre in communication technology:
The signal that is sent along optical fibres in telecommunication system is in the infrared region
of the electromagnetic spectrum. The electrical signals are converted into pulses of infrared
inside the fibres which can be converted back into electrical signals
Mark scheme
information /message / music/sound / signal / data (encoded as pulses of light) sent B1
light (travels along fibre) or infra-red (radiation) B1
light detected (at far end) or message decoded or total internal reflection mentioned
Diode function:
diode B1
prevents / stops the backward current or allows only one direction of current
Background radiation:
,(radiation) always present / due to environment / in absence of radioactive sample / natural
(radiation)
Precaution while using radioactive isotopes:
any two of: • (distance): tongs /manipulator/ centre of cardboard box • (absorption): lead gloves /
suit/lead glass screen / googles /glasses • (time): limit exposure time / keep in box until needed /
film badge
(c) Standard atmospheric pressure is 0.76 m of mercury. Suggest a reason why the value of
h in
(b) is lower than this
Not temperature because:
-temp only increases pressure if volume is constant
Velocity- same direction as object moving
Acceleration- same direction as resultant force/When an object is speeding up, the acceleration
is in the same direction as the velocity. Thus, this object has a positive acceleration. In Example
B, the object is moving in the negative direction (i.e., has a negative velocity) and is slowing
down
file:///C:/Users/Sumaiya%20Mahmud/Downloads/Documents/igcse_physics_(19)_-_cathode_ra
y_oscilloscopes_001.pdf
,REFRACTIVE INDEX IS GIVEN OF SECOND MEDIUM WITH RESPECT TO FRIST MEDIUM
: Ldr parallel across bulb ldr gets low current so bulb should grt more current
Its gets high voltage bcs resistance increases and across parallel voltage is same. V=IR
Brightness of bulb depends on power
, The rate of thermal radiation is determined by the color, txture, surface temperature and surfac
Solar power:
two advantages from: no polluting gases /quiet/low maintenance / can be placed on roofs /
clean/ cheap to run B2 two disadvantages from: intermittent supply / unattractive / takes up
space/ uses land /d.c. output
Internatl energy-sum of total kinetic energy and potential energy of all molecules
How temp changes whil transferring energy to surrounding?
\
Optical fibre in communication technology:
The signal that is sent along optical fibres in telecommunication system is in the infrared region
of the electromagnetic spectrum. The electrical signals are converted into pulses of infrared
inside the fibres which can be converted back into electrical signals
Mark scheme
information /message / music/sound / signal / data (encoded as pulses of light) sent B1
light (travels along fibre) or infra-red (radiation) B1
light detected (at far end) or message decoded or total internal reflection mentioned
Diode function:
diode B1
prevents / stops the backward current or allows only one direction of current
Background radiation:
,(radiation) always present / due to environment / in absence of radioactive sample / natural
(radiation)
Precaution while using radioactive isotopes:
any two of: • (distance): tongs /manipulator/ centre of cardboard box • (absorption): lead gloves /
suit/lead glass screen / googles /glasses • (time): limit exposure time / keep in box until needed /
film badge
(c) Standard atmospheric pressure is 0.76 m of mercury. Suggest a reason why the value of
h in
(b) is lower than this
Not temperature because:
-temp only increases pressure if volume is constant
Velocity- same direction as object moving
Acceleration- same direction as resultant force/When an object is speeding up, the acceleration
is in the same direction as the velocity. Thus, this object has a positive acceleration. In Example
B, the object is moving in the negative direction (i.e., has a negative velocity) and is slowing
down
file:///C:/Users/Sumaiya%20Mahmud/Downloads/Documents/igcse_physics_(19)_-_cathode_ra
y_oscilloscopes_001.pdf
,REFRACTIVE INDEX IS GIVEN OF SECOND MEDIUM WITH RESPECT TO FRIST MEDIUM
: Ldr parallel across bulb ldr gets low current so bulb should grt more current
Its gets high voltage bcs resistance increases and across parallel voltage is same. V=IR
Brightness of bulb depends on power
, The rate of thermal radiation is determined by the color, txture, surface temperature and surfac
