In most cases the temperature must increase for thermal expansion to occur. Most substances expand as temperature increases because the atoms or molecules vibrate faster as temperature increases and experience greater separation.
<h2>Answer: decreasing</h2>
An RC circuit is an electrical circuit composed of resistors and capacitors, where the charging time
of the circuit is proportional to the magnitude of the electrical resistance
and the capacity
of the capacitor.
As shown below:
In this context, the electrical resistance is the opposition to the flow of electrons when moving through a conductor.
Therefore:
<h2>When a capacitor is being charged in an RC circuit, the current flowing through a resistor <u>decreases</u>.</h2>
And the correct option is b.
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


Answer:

Explanation:
Given:
angular speed of rotation of friction-less platform, 
moment of inertia with extended weight, 
moment of inertia with contracted weight, 
<u>Now we use the law of conservation of angular momentum:</u>



The angular speed becomes faster as the mass is contracted radially near to the axis of rotation.