Which of the following ammeters may be used to measure alternating currents? i. moving-coil ammeter ii. moving-iron ammeter iii. hot-wire ammeter
i and ii only
ii and iii only
i and iii only
i, ii, and iii
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the answer is wrong.
An alternating current can be measured by...............hot-wire ammeter, moving iron ammeter, and moving coil galvanometer to which a rectifier is attached to convert the a.c. to a d.c.
ref: New school physics page 447.
pls d answer is wrong....it is supposed to b ii and iii...because moving coil ammeter cannot measure a.c bcos the magnetic field is polarised and so d needle acts in opp direction for each direction of current nd so can measure on d.c
The correct answer is:
B. ii and iii only
Here's an explanation of each type of ammeter:
Moving-coil ammeter: This type of ammeter is primarily designed for measuring direct current (DC). It can measure alternating current (AC) only if it is specifically designed for that purpose (such as a rectifier ammeter), but generally, traditional moving-coil ammeters are not suitable for AC measurement.
Moving-iron ammeter: This type of ammeter can measure both AC and DC. It operates on the principle of the magnetic effect of the current and can handle alternating currents effectively.
Hot-wire ammeter: This ammeter is specifically designed to measure alternating current. It works on the principle of heating produced by the current flowing through a wire, making it suitable for AC measurements.
Thus, the ammeters that can measure alternating currents are the moving-iron ammeter and the hot-wire ammeter, leading to the correct answer being B. ii and iii only.
MYSCHOOL MYSCHOOL
PLS CHANGE THIS ANS
The correct ans is B
See reason below πππππππππππππππππππππππ
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Moving coil instruments are used to measure the DC quantities only. So, moving coil ammeter is used to measure DC current. The moving iron instrument can be used to measure both AC and DC quantities.
Greetings, The Myschool Team.
The correct answer is B(ii and iii only) and not D(i, ii and iii). A moving coil ammeter operates on the principle of the force induced on a current carrying conductor in a magnetic field. A moving coil ammeter cannot measure alternating current as the reversal in direction of current would lead to the coil being displaced in opposite directions equally, leading to no net displacement. All other ammeters listed can measure alternating current. Thus, the correct answer is B(ii and iii only) and not D (i, ii and iii). Thank you.
