A light bulb and a solenoid are connected in series to a battery. An irod rod is thrust rapidly into the solenoid and later rapidly removed. The bulb 1. No change in, Dims out 2. Brightens in, No change out 3. Dims in, Brightens out 4. No change in, Brightens out 5. Dims in, Dims out 6. Brightens in, Brightens out 7. Brightens in, Dims out 8. Remains brighter the entire time 9. No change in or out 10. Dims in, No change out 006 10.0 poi

The correct option is;

3. Dims in, Brightens out

Explanation:

Inserting the iron rod into the current carrying solenoid causes the inductance and hence impedance to increase. Increasing impedance increases the circuit total resistance to current flow, thereby reducing the amount of  electric current, which causes the light bulb to dim as the iron rod enters the solenoid.

The reverse happens as the iron rod is rapidly removed.

The inductive reactance is given by;

Inductive reactance, = 2·π·f·L

Where;

L = Inductance (Henries)

ω = Angular velocity in radians

f = Frequency

current, I is given by

Therefore

Iron rod entering the solenoid increases inductance, decreases the current and the bulb is dimmer.

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min