Q.
The magnetic needle of an oscillation magnetometer makes 10 oscillations per minute under the action of earth's magnetic field alone. When a bar magnet is placed at some distance along the axis of the needle it makes 14 oscillations per minute. If the bar magnet is turned so that its poles interchange their position, then the new frequency of oscillation of the needle is
see full answer
Start JEE / NEET / Foundation preparation at rupees 99/day !!
21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya
a
10 vibrations Per minute
b
14 vibrations per minute
c
4 vibrations per minute
d
2 vibrations per minute
answer is D.
(Unlock A.I Detailed Solution for FREE)
Ready to Test Your Skills?
Check your Performance Today with our Free Mock Test used by Toppers!
Take Free Test
Detailed Solution
T=2πIMHFor I case: 6010=2πIMH ............(i)For II case: 6014=2πIM(H+R) ............(ii)Equation (ii) / (i),3076=HH+RR=2425H ....(iii)For III case: 60n=2πIM(H-R)=2π x 5IMH-2425H ∵R=2425H=2π x 5 x IMH ........(iv)From equations (i) and (iv), we get60n=30⇒ n = 2 vibrations per minute.
Watch 3-min video & get full concept clarity