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When the horizontal deflecting plates of a CRO are kept at the ground potential and 30 V dc is applied to the vertical deflecting plates, then the picture observed on the screen would be
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- a spot approximately 3 cm away from the centre
- a vertical line 2 cm long
- a vertical line approximately 3 cm long
- two spots 2 cm vertical above each other
Correct Option: C
Total length observed will be proportional to 2Vm
= 2√2 × 30
30 V dc causes 1 cm deflection from the centre point.
Length observed = 2√2 cm = 3 cm.
