current electricity | basic questions | Physics class 12 | advguruji

current electricity | basic questions | Physics class 12 | advguruji | Physics Advocate

Q1.

An electron beam has an aperture of 2 mm². A total of 7 × 10¹⁵ electrons flow through any perpendicular cross-section per second. Calculate the current density of the electron beam.

Q2.

The charge in a given wire varies with time, given by -

q = 3t³ - t²

Where, q in 'C' and t in 'secs'.

Find the current flowing in the wire at 4th second.

Q3.

The current flowing in a conductor is the function of time, given by -

I = 8t - 3

Where, I in 'Ampere' and t in'secs'.

Find the total charge flowed in first 5 seconds in the conductor.

Also, find the charge which flowed from 6th to 8th second.

----------------------------------------------------------------------

ANSWERS

A1.

560 Am-²

A2.

136 A

A3.

85 C, 106 C

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