China Civil UAV Theory Questions — Questions 326–335

The S value is the number of cells in series; the P value is the number of parallel groups. Series connection increases voltage; parallel connection increases capacity. 3S2P means 3 cells in series × 2 groups in parallel.

This question tests the definition of battery capacity units and unit conversion. 1Ah means the battery discharges at 1A for 1 hour. 1A = 1000mA, so 10Ah = 10A × 1h = 10000mA × 1h: discharging at 10000mA, it lasts 1 hour. Option B is correct.

This question tests the battery capacity concept and mA-to-A conversion. 6000mAh = 6000mA × 1h = 6A × 1h.

This question tests the Li battery nominal voltage of 3.7V and power battery series/parallel markings. Series voltage = 3.7V × 3S = 11.1V: three Li cells in series give 11.1V.

When Li cells are connected in series, the pack voltage is the sum of the cell voltages, and a Li cell's nominal voltage is 3.7V. Series count = 22.2V ÷ 3.7V = 6, so it is 6 cells of 3.7V Li in series: a 6S Li battery.

A normal prop rotates counterclockwise viewed from above, abbreviated CCW (counter-clockwise). A reverse prop rotates clockwise viewed from above, abbreviated CW (clockwise).

Study note: do not pick the option that copies the millimeter numbers. Propeller sizes are calculated in inches, 1 inch = 2.54 cm. This propeller's length 254mm = 10 inches, and its pitch 114mm = 4.5 inches. The model is 1045: 10 means 10-inch length, 45 means 4.5-inch pitch.

Study note: do not pick the option that copies the millimeter numbers. Propeller sizes are calculated in inches, 1 inch = 2.54 cm. This propeller's length 381mm = 15 inches, and its pitch 127mm = 5 inches. The model is 15×5: 15 means 15-inch length, 5 means 5-inch pitch.

A normal prop rotates counterclockwise viewed from above, abbreviated CCW (counter-clockwise).

Study note: KK is cheap, DJI is not open-source, the rest are open-source. APM is open-source and based on the Arduino platform, not the Android platform.