9702/Oct Nov/11/2015/Q4

A calibration graph is shown for an ammeter whose scale is inaccurate.

Two readings taken on the meter at different times during an experiment are 0.13 mA and
0.47 mA.

By how much did the current really increase between taking the two readings?

A 0.30 mA
B 0.35 mA
C 0.40 mA
D 0.44 mA

Solution:
Answer: A

When ammeter reading = 0.13mA, the current = 0.14mA
When ammeter reading = 0.47mA, the current = 0.44mA
The current increase between taking the two reading is 0.44mA - 0.14mA = 0.3mA

Reference: PYQ - Oct/Nov 2015 Paper 11 Q4

9702/May Jun/12/2015/Q4

The arrow represents the vector R.

Which diagram does not represent R as two perpendicular components?

Solution:
Answer: C.

When facing such types of question, it is best to tackle it by drawing on the question paper itself.

The vector sum of the two perpendicular components should provide a resultant equal to the vector R shown.

By completing the diagram (by the parallelogram method, for example), we can observe that only choice C does not provide a resultant similar to the vector R shown. Instead, the resultant in C has a downward direction and thus, cannot be equal to the vector R shown.

Reference: PYQ - May/Jun 2015 Paper 12 Q4