Two lenses with focal lengths 10cm and 20cm and made of same material are placed coaxially

Consider an electrical transformer has 10 loops on its primary coil and 20 loops on its secondary coil. What is the voltage in t

Arlecino [84]

Answer:

240 V

Explanation:

number of turns in primary coil, Np = 10

Number of loops in secondary coil, Ns = 20

Voltage in primary coil, Vp = 120 V

Let the voltage in secondary coil is Vs.

So, Vs / Vp = Ns / Np

Vs / 120 = 20 / 10

Vs / 120 = 2

Vs = 240 V

Thus, the voltage in secondary coil is 240 Volt.

4 0

3 years ago

E Describe the meaning of a line crossing the x-axis in a<br> velocity-time graph.

gizmo_the_mogwai [7]

Answer:

A line crossing the x-axis in a velocity-time graph means that the moving object has changed its direction.

Explanation:

Velocity-Time graph:

A velocity-time graph is a two dimensional graph with velocity at its y-axis and time at its x-axis. At any point, value of y represents the velocity and value of x represents the time. The slope of the graph gives us the acceleration or deceleration of the moving object.

In a velocity-time graph:

- A straight line represents constant velocity.

- A diagonal line means that the velocity of a body is changing.

*Referring to the figure attached with the answer*

The velocity of the moving object increases at a constant rate for the first 10 minutes. Then the velocity is 60 m/min for the next 5 minutes. After that the velocity is decreasing. Till 30th minute when the velocity is at 0 m/min.

What happens here?

Velocity is a vector quantity. It has some direction. In a velocity-time graph, we are only concerned with two directions of velocity:

- Forward direction

- Backward direction

So, the object stops at 30th minute and starts moving in the reverse direction after that with an increasing velocity. <u>The point where the line cuts the x-axis is basically the point where the object starts moving in the reverse direction.</u>