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Question 21M.2.HL.TZ2.7a.iii

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Date May 2021 Marks available [Maximum mark: 2] Reference code 21M.2.HL.TZ2.7a.iii
Level HL Paper 2 Time zone TZ2
Command term Calculate Question number a.iii Adapted from N/A
a.iii.
[Maximum mark: 2]
21M.2.HL.TZ2.7a.iii

The primary coil of a transformer is connected to a 110 V alternating current (ac) supply. The secondary coil of the transformer is connected to a 15 V garden lighting system that consists of 8 lamps connected in parallel. Each lamp is rated at 35 W when working at its normal brightness. Root mean square (rms) values are used throughout this question.

(a.iii)

Calculate the current in the primary of the transformer assuming that it is ideal.

[2]

Markscheme

total power required = 280 «W»
OR
uses factor 3300450
OR
total current = 18.7 « A»

current = 2.5 OR 2.6 «A» 


Award [2] marks for a bald correct answer.

Allow ECF from (a)(ii).