Question

ANSWER ALL 4 QUESTIONS PLEASE

1-You have set up an LRC series circuit and are observing the voltage drop across the resistor on an ideal oscilloscope. If you disconnect the oscilloscope, does the current in the circuit change? Why or why not?

2-When a line light source with spectral lines is observed through a diffraction grating

I. the blue lines are closer from the center than the red lines.

II. the blue lines are farther from the center than the red lines.

3-A lens of unknown focal length is given to you while you are outside on a sunny day. With just a ruler how can you measure the focal length?

4-An experimental parameter measured at 10 ? 2 is compared with a previous measurement of 6 ? 1. Do the two values agree? Explain your reasoning.

Answer 1

Q1.

as it is an ideal oscilloscope, it has infinity resistance.

so it wont interfer with the circuit when connected.

hence when it is disconnected, the current in the circuit wont change.

Q2.

for diffraction grating, distance from central bright line is lambda*D/d

where D is distance of screen from the grating and d is grating slit width.

as it is proportional to wavelength lambda , higher the lambda, higher the distance from center.

as wavelength of red light is higher than blue light ,'

blue lines will be closer to center than the red line.

Q3.

use the lens to focus the sun light onto a screen .

move the lens till it is a focused dot.

then distance from the lens to the screen will be the focal length.

(as image of a ray coming from infinity will be formed at focus)

Q4.

as both the values have seprate measurements and error percentage, these two values dont agree.