Answer:
The time rate of change of flux is
Explanation:
Given :
Current A
Area of plate
Plate separation m
(A)
First find the capacitance of capacitor,
Where
F
But
Where
Now differentiate above equation wrt. time,
Therefore, the time rate of change of flux is
Answer:
B. Maximum velocity of ejected electrons.
Explanation:
The ejection of electrons form a metal surface when the metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength or higher frequency (or equivalently, above a threshold frequency), which leads to the enough energy of the wave to incident and get absorbed to the exposed surface emits electrons. This phenomenon is known as the photoelectric effect or photo-emission.
The minimum amount of energy required by a metal surface to eject an electron from its surface is called work function of metal surface.
The electrons thus emitted are called photo-electrons.
The current produced as a result is called photo electricity.
Energy of photon is given by:
where:
h = Planck's constant
frequency of the incident radiation.
Answer:
An example of kinetic energy is a <u><em>car coming to a stop</em></u>
Explanation:
Kinetic energy is the energy that a body or system possesses due to its movement. In physics this energy is defined as the amount of work necessary to accelerate a body of a certain mass and in rest position, until reaching a certain speed. This energy obtained will remain unchanged as long as this body does not vary its speed. That is, kinetic energy measures how many changes an object that is moving can cause.
<u><em>An example of kinetic energy is a car coming to a stop</em></u>. If the car is moving and comes to a stop, there is a change in speed, therefore in movement, eventually producing a change in kinetic energy. This energy depends on the mass of the body, in this case the car, and the speed. As the speed decreases, the kinetic energy will decrease.
Answer: 3 m.
Explanation:
Neglecting the mass of the seesaw, in order the seesaw to be balanced, the sum of the torques created by gravity acting on both children must be 0.
As we are asked to locate Jack at some distance from the fulcrum, we can take torques regarding the fulcrum, which is located at just in the middle of the length of the seesaw.
If we choose the counterclockwise direction as positive, we can write the torque equation as follows (assuming that Jill sits at the left end of the seesaw):
mJill* 5m -mJack* d = 0
60 kg*5 m -100 kg* d =0
Solving for d:
d = 3 m.