UPSC Prelims 2023 · GS Paper I
Question 54: Science and Technology
Consider the following actions :
- 1.Detection of car crash/collision which results in the deployment of airbags almost instantaneously
- 2.Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive
- 3.Detection of the tilt of the smartphone which results in the rotation of display between portrait and landscape mode
In how many of the above actions is the function of accelerometer required?
AnswerUPSC’s answer is (c).
An accelerometer measures acceleration, including the pull of gravity. A crash causes a sudden deceleration that triggers airbag deployment. A laptop in free fall shows a near-zero reading, which tells the hard drive to park its heads. A tilting smartphone changes the direction of gravity on the sensor, which flips the display between portrait and landscape. All three use an accelerometer.
- 1. Crash detection depends on sudden deceleration.
- 2. Free fall is detected through the change in acceleration.
- 3. Tilt is sensed from the direction of gravity.
How you could have got this
No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Only one undercounts; all three actions use an accelerometer.
- (b) Only two undercounts; free fall and tilt detection also use it.
- (c) Correct: airbags, free-fall protection and screen rotation all use accelerometers.
- (d) Accelerometers are central to all three, so not none.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2023, General Studies Paper I, Series A. The paper on upsc.gov.in.