Electric Charges and Fields

Class 12 physics. chapter 1.

Can electrostatics be applied by the observer to study charge when:
1. The charge is at rest, the observer is moving
2. Both charge and observer are moving; the charge is at rest relative to the observer

1. No

2. Yes

Electrostatics applies only when the charge is stationary relative to the observer. If the charge moves (or the observer runs past the charge), a magnetic field is also produced. This is a favorite "trick" question to test if you understand the boundary of Electrostatics.

Whats the value of ‘e. ‘

e = basic unit of charge= 1.602 × 10^-19 C

"At the macroscopic level, the quantisation of charge... can be ignored."

what does it mean??

“Charge comes in tiny packets (electrons), but when you have BILLIONS of them, you stop noticing the packets. It's like sand on a beach — zoom in and you see individual grains, but from far away it just looks smooth.“

Basically:
- Property of quantisation still applies

- You just ignore the formula q=ne.
since the values are wayy bigger.

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