Question
Q 1-when current passes through a solenoid .then what happens to the length of solenoid?
Q2-a current carrying wire carrying current i normally into the paper at the centreof current carring circular ring.the magnetic force acting on the circular ring is ?
Q3- To increase the current through the solenoid from 1A TO 2A ,30J work is done by thr battery.work done by the same battery in increasing the current from 3A TO 4A IS?
Q4- When a closed looop is held stationary in magnetic field b/w north & south pole of 2 permanent magnets of different dipole moments , then current will be induced in the loop or not?
1. the length will decrease as the current in the two consecutive turns of the solenoid are in same direction. which will create an atrraction.
2. since B produced by the wire is parllel to the direction of dl so net force will be 0
3.dw = Lidi first take limit 1 to2 and w=30 to find the L (INTEGERATE)
After than again use the above formula taking limit 3 to 4 .put L here ,L= 20
the answer is 70J.
4. I think no emf will be induced as the flux is not changing.
These answers by NIKHIL VARSHNEY are correct
Read 1 Solution.
1. the length will decrease as the current in the two consecutive turns of the solenoid are in same direction. which will create an atrraction.
2.consider a small portion of length Rdø the force acting on it will be dF= μ2 I1 I2dφ/2π.4π now integerate it taking limit 0 to 2π
3.dw = Lidi first take limit 1 to2 and w=30 to find the L (INTEGERATE)
After than again use the above formula taking limit 3 to 4 .put L here ,L= 20
the answer is 70J.
4. I think no emf will be induced as the fluxis not changing.