Physics Answers

prove divD= volume charge density using gauss law .Also find the capacitance of two concentric spherical metal shells radii a and b.

on a hypothetical planet X with an unknown value for g, the period of a swinging pendulum with a string length of .75 meters is a 1.8 s calculate the value of "g" on plnaet X

An anti-aircraft shell is fired vertically upward with a muzzle velocity of 100m/s. Calculate the maximum height it can attain

The sum of a number of proton and neutron is called:

A. Atomic number

B. Mass number

C. Isotopes

D. None of these

1. What is the number of a neutron in the nucleus of uranium:

A. 94

B. 145

C. 235

D. Same number

E. Different for different isotopes

An X-ray line of wavelength 0.53832A0 is found to be emitted from an X− ray tube with (Z= 30) target in addition to the characteristic Kα line of Zinc of wavelength 1.43603A0 . If the unkown line is due to an impurity in the target, obtain the atomic number of the impurity.

The Hydrogen atom in its ground state is excited by means of a monochromatic radiation of wavelength 970.6A0 . How many different wavelengths (transitions) are possible in the resulting emission spectrum ? [NB: you have to represents them on a diagram]. Find the longest wavelength amongst these.

•In a circuit with a 100 ohm resistor and a 47 ohm resistor in series, there are 20 mA of current through the 100 ohm resistor. How much current is through the 47 ohm resistor?

In the Helium-Neon laser, lasing occurs between two excited states of the neon atom. However, in many lasers lasing occurs between the ground state and an excited state. Consider such a laser that emits at wavelength λ = 550 nm. If a population inversion is not generated, (i) what is the ratio of the population of atoms in state Ex to the population in the ground state E0 with atoms at room temperature? For the condition in (i), at (ii) what temperature would the ratio Nx/N0 be 1/2?.

How much energy (in Joules) will be produced on complete fission of 1 kg of Uranium (235U), considering that only 0.1% of mass is converted into energy.