Recent questions in Physics

The photoelectric cut-off voltage in a certain experiment is 1.5 V. What is the maximum kinetic energy of photoelectrons emitted ?

asked Dec 23, 2013 by thanvigandhi_1

1 answer

The work function of caesium metal is $2.14 \;eV$. When light of frequency $ 6 \times 10^{14}Hz$ is incident on the metal surface , photoemmision of electron occurs. What is the stopping potential of the emitted photoelectrons ?

asked Dec 23, 2013 by thanvigandhi_1

1 answer

The maximum frequency of X-rays produced by 30 kv electrons is

asked Dec 23, 2013 by thanvigandhi_1

1 answer

Angle between lines of force and equi-potential surface is?

asked Dec 20, 2013 by balaji.thirumalai

1 answer

If the space between two plates of a capacitor is filled with liquid of dielectric constant K, the capacitance of the capacitor:

asked Dec 20, 2013 by balaji.thirumalai

1 answer

Two plates are 5 cm apart, a potential difference of 10V is applied between them. What is the electric field between the plates?

asked Dec 20, 2013 by balaji.thirumalai

1 answer

A condenser of $100\; \mu F$ is charged to $50 V$. What is its energy in Joules?

asked Dec 20, 2013 by balaji.thirumalai

1 answer

Radii of two spheres forming a spherical condenser are 0.3 and 0.4m. If dielectric constant of medium is 4 and medium is completely filled in between, find the capacity of the condenser..

asked Dec 20, 2013 by balaji.thirumalai

1 answer

If three equal charges are placed on three corners of square and force between $q_1$ and $q_2$ is $F_2$, and the force between $q_1$ and $q_2$ is $F_3$, find $F_3/F_2$

asked Dec 20, 2013 by balaji.thirumalai

1 answer

A p-n photodiode is made of a material with a band gap of 2.0eV. The minimum frequency of the radiation that can be absorbed by the material is nearly :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

The circuit is equivalent to

asked Dec 16, 2013 by thanvigandhi_1

0 answers

If the lattice parameter for a crystalline structure is 3.6 A, then the atomic radius in fcc crystal is :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

If M ( A;Z), $M_p\: and \: M_n$ denote the masses of the nucleus $ ^A_ZX,$ proton and neutron respectively in units of $u\: (1u=931.5Mev/C^2)$ and BE represents its bonding energy in MeV, then :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

Two nuclei have their mass numbers in the ratio of 1 : 3. The ratio of their nuclear densities would be :

asked Dec 16, 2013 by thanvigandhi_1

1 answer

Two radioactive materials $ X_1\: and\: X_2$ have decay constants $ 5\lambda\: and\: \lambda$ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of $ X_1$ to that of $ X_2$ will be $ \large\frac{1}{e}$ after a time :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

The ground state energy of hydrogen atom is -13.6eV. When its electron is in the first excited state, its excitation energy is :

asked Dec 16, 2013 by thanvigandhi_1

1 answer

A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of $ 3 \times 10^6\: ms^{-1}$. The velocity of particle is :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

The work function of a surface of a photosensitive material is 6.2 e.V. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

In a a.c circuit the e.m.f (e) and the current (i) at any instant are given respectively by :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

A long solenoid has 500 turns. When a current of 2 ampere is passed through it, the resulting magnetic flux linked with each turn of the solenoid is $ 4 \times 10^{-3}\: \omega b$. The self - inductance of the solenoid is :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

Curie temperature is the temperature above which :

asked Dec 16, 2013 by thanvigandhi_1

0 answers

A galvonometer of resistance $ 50 \Omega$ is connected to a battery of 3V along with a resistance of $ 2950 \Omega$ in series. A full scale deflection of 30 divisions is obtained in the galvonometer. In order to reduce this deflection to 20 divisions, the resistance in series should be :

asked Dec 16, 2013 by thanvigandhi_1

1 answer