Can u please write two pages on lens history and what are lenses.... Applications in today's life... Please don't copy from online sources... If its ur own work one page is also good

In the experiment: To determine the resistivity of a semiconductor using Four probe method.

What does the floating potential mean? Like what's the difference between potential and floating potential?

Also what does the correction factor in this experiment signify? Like why do we need the correction factor in this experiment?
The value of the correction factor in this experiment is G7 which is 2ln2.

47. Suppose that 1 kg of U235 undergoes fission by thermal neutrons. Compute the masses (or mass equivalents) in grams for the following, which are produced: 1. neutrons, 2. γ-rays, 3. β-rays, 4. neutrinos, 5. kinetic energy, 6. fission products.

1. Light of wavelength 620nm in air is incident on a surface of a flat piece of glass with an index of refraction of

1.50 with an angle of incidence of 30°.

a.What is the angle of refraction?

-Answer: 19.5°

b. Find the wavelength and frequency of light in glass.

Answer: 413nm, 4.84x10¹⁴Hz

c.Explain under what circumstances “total internal reflection” can be observed at the boundary between air

and this piece of glass. Be as specific as possible.

Mass m = 0.1 kg moves to the right with speed v = 0.54 m/s and collides with an equal mass initially at rest. After this inelastic collision the system retains a fraction = 0.9 of its original kinetic energy. If the masses remain in contact for 0.01 secs while colliding, what is the average force in N between the masses during the collision? Hints: All motion is in 1D. Ignore friction between the masses and the horizontal surface. You will probably need to use the quadratic formula to solve the resulting equations. VR must be greater than VL since the masses can't pass through each other!

Compare and contrast any TWO of the following thermal analysis techniques;

(i) Differential Scanning Calorimetry, DSC,

(ii) Differential Thermal Analysis, DTA,

(iii) Thermogravimetric Analysis, TGA,

18 marks so please give a proper answer

A certain transverse wave is described by y(x,t)=Bcos[2π(xL−tτ)], where B = 5.40 mm , L = 28.0 cm , and τ = 4.00×10−2 s . a)Determine the wave's wavelength. b)Determine the wave's speed of propagation

A microwave oven is a kitchen appliance. Is it safe to stand by a microwave oven when it is cooking food? Should we use microwave to cook the egg in shell? Explain very accurately and in detail, using physics.

Suppose I have a current source of 1.0 Amperes flowing through each of the following coils. What is the magnetic field in Tesla and in Gauss at the stipulated points? 1) At the center of a single 200-turn coil with a radius of 103 mm. 2) A the midpoint between two 200-turn coaxial coils of radii 103 mm and separated by a distance of 103 mm. (Assume the currents are arranged so that the fields add constructively). 3) At the center of a 565-turn, 146 mm-long solenoid of radius 34.1 mm.

A wire carrying a 30 A current pass between two strong bar magnets and experiences a 2.16 N force on the 4.00 cm of wire in the field.
(i) Show the direction of the force in the diagram.   
(ii)What is the strength of the magnetic field?

Consider Hydrogen with an electron in the n = 2 state.

a) Find the Energy of the electron.

The electron is in the 2p state. Then it moves to the 1s state.

b) Calculate the energy of the emitted photon.

The atom is placed in a magnetic field of 500 T.

c) Find the energies of all the emitted photons. Don't worry about electron spin.

A capacitor C1 =1F is connected to a 1V battery using a wire with a total resistance R = 1Ohm

Suppose after the charging is complete the capacitor C1 is connected to another capacitor C2 = 2 F using a wire with a total resistance of R =0.3 Ohm. Now the first capacitor discharges while the second one charges.

2.8 [1pt] How much charge was transferred through the resistor R during the discharge?

ANSWER

2.9 [1pt] How much energy was dissipated in the resistor R during the discharge

ANSWER

Let’s derive the differential equation describing the discharge in this 2-capacitor circuit. Let’s label the charge on the capacitor C1 as q1(t) and the charge on the capacitor C2 as q2(t).

2.10 [1pt] Sketch the circuit diagram, label the charges and their signs at the capacitors plate, and link q1(t) and q2(t).

Hint, what is q1(t=0) and q2(t=0) (t=0 is the instant the connection was made)?

ANSWER

2.11 [1pt] Express the current through the resistor in terms of the charge derivative and write down the voltages across both capacitors and the resistor add up to zero. From the resulting equation, deduce the characteristic charging time without solving it.

ANSWER

Does the resistance torque change as leg position is changed? Explain, based on the average scores for perceived exertion, which leg position is easiest to perform and which is hardest. Why are there differences in perceived exertion for the different leg positions?