In C.R.O grid is always connected with potential:
Negative
Positive
High positive
Zero positive
Which is not an e.m.f source:
Generator
Solar cell
Battery
Rheostat
Application of electrostatic is:
Car painting
Photocopying
Extracting of dust
All of these
Vibratory motion
Damped motion
Linear motion
The intensity level of train siren is:
150 dB
100 dB
130 dB
120 dB