BI
Hall voltage V =
H ntq
alternating current/voltage x = x sin ωt
Question
Physics
CAIE2024
BI
Hall voltage V =
H ntq
alternating current/voltage x = x sin ωt
Question
Physics
CAIE2024
BI
Hall voltage V =
H ntq
alternating current/voltage x = x sin ωt
Question
Physics
CAIE2024
(a) State what is meant by the frequency of an alternating current.
...................................................................................................................................................
............................................................................................................................................. [1]
(b) An alternating current I in a resistor of resistance 680 Ω varies with time t according to
I = 3.5 sin (40πt)
where I is in A and t is in s.
(i) Show that the period of the alternating current is 50 ms.
[1]
(ii) On Fig. 8.1, sketch the variation of I with t between t = 0 and t = 100 ms.
Question
Physics
CAIE2023
2
alternating current/voltage x = x sinωt
o
radioactive decay x = x exp(-λt)
o
Question
Physics
Edexcel2023
An induction hob consists of a coil beneath a sheet of ceramic material. The coil is
connected to an alternating current (a.c.) supply as shown.
pan
ceramic
material
coil connected to
an a.c. supply
(a) A steel pan containing water is placed on the induction hob.
Explain why the pan becomes hot when the supply is switched on.
(4)
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
(b) The a.c. supply to the coil in an induction hob has a much higher frequency than
normal mains frequency.
Explain why this is an advantage in this case.
(2)
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
..................................................................................................................................................................................................................................................
(Total for Question 11 = 6 marks)
*P71915A0828*
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
DO
NOT
WRITE
IN
THIS
AREA
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
OD
PMT
Question
Physics
Edexcel2022
Power supplies provide either alternating or direct currents and potential differences.
(a) A power supply produces an alternating potential difference (p.d.). The p.d. has a
period of 0.02 s and a peak value of 4.0 V.
(i) Calculate the frequency of the supply.
(1)
...................................................................................................................................................................................................................................................
Frequency =
.......................................................
(ii) Calculate the root‑mean‑square p.d.
(1)
...................................................................................................................................................................................................................................................
Root‑mean‑square p.d. =
.......................................................
(b) It is possible to convert alternating currents and p.d.s, to direct currents and p.d.s
using diodes.
The power supply provides an input V to the circuit shown. The circuit includes
in
four diodes D , D , D and D and a resistor R. The circuit produces an output
Question
Physics
CAIE2016
2
BI
Hall voltage V =
H ntq
alternating current/voltage x = x sin (cid:90)(cid:3)(cid:3)t