Static charge is developed due to air friction. This can result in combustion. So, metallic chains is used to discharge excess charge.
The vehicles carrying inflammable fluids usually have metallic chains touching the ground :
Held on 5 Apr 2024 · Verified 6 Jul 2026.
To protect tyres from catching dirt from ground
To alert other vehicles
It is a custom
To conduct excess charge due to air friction to ground and prevent sparking
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A short bar magnet placed with its axis at $30^{\circ}$ with an external field of 800 Gauss, experiences a torque of $0.016 \mathrm{~N}. \mathrm{m}$. The work done in moving it from most stable to most unstable position is $\alpha \times 10^{-3} \mathrm{~J}$. The value of $\alpha$ is $\_\_\_\_$.
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