CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A charged capacitor is allowed to discharge through a resistor by closing the key at the instant t=0. At J the instant t=(ln4)μs, the reading of the ammeter falls half the initial value. The resistance of the ammeter is equal to

214469.png

A
0.5Ω
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
1Ω
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2Ω
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
4Ω
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 2Ω
During discharging, current , i(t)=i0et/RC

If r be the resistance of ammeter, net resistance , R=2+r

When t=ln4,i=i0/2i0e(ln4/RC)=i0/2

or e(ln4/RC)=2

take ln on both sides, ln4/RC=ln2

or RC=ln4ln2=2ln2ln2=2

or R=2C=2/0.5=4

or 2+r=4r=2Ω

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Dielectrics
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon