The car's speed is 240km/4hr= 60km/hr.
There's not enough information given in the question to determine its velocity.
Answer:
C. Supervising the game to make sure teams are playing fairly
Answer:

Explanation:
As we know that magnetic field due to torroid is given as

this is approximately constant magnetic field along the axis of the torroid
now the flux linked with one coil of the torroid is given as


now total flux of N number of coils is given as

now we know that self inductance is the property of coil in which flux of the coil will link with the current in the coil
So we know that

