Possible units for the disintegration constant λ are:

To achieve DC from AC, AC will be applied across

Work function is

If the velocity of electron entering in velocity selector is V < E/B , the electron will

In a half wave rectifier, the frequency of the input is N, the frequency and form of the output will be

When a photon collides with an electron which of the following of photon increases?

Activity of a sample is initially 320 counts per second. At the end of 90 minutes it gives 40 counts per second. What is the half-life of the element in sample?

The emission of β-particle from polonium-218 results in the formation of

Paschen series is obtained when all the transitions of electron terminate on.

To ionize hydrogen atom from its ground state energy required is

If momentum of a particle is doubled then de-Broglie wavelength become

The energy of electron in an excited stated of hydrogen atom is −1.5 eV. What are the kinetic and potential energies of the electron in this state?

According to the equation $$_Z^AX\rightarrow Y+3\alpha$$  particles, what are the atomic and mass numbers of ‘Y’?

The Einstein’s photo-electric equation is based upon the conservation of

A transmitter radiates 30 $$\mu$$ W at 6.63 mm wavelength. The number of photons emitted per second are:

A proton when accelerated through a potential difference of V volt has a wavelength λ associated with it. An a - particle in order to have the same wavelength λ must be accelerated through a potential difference of

Three infinite straight wires A, B, and C carry currents as shown. The net force on the wire B is directed.

If a current flow through the wire directed out of the paper, the magnetic field is represented by

The instantaneous voltage “V” generated by a rotating coil in a magnetic field has the form V=V₀ Sin 2πft here 2πf is

The half-life period of a radioactive sample depends upon

Two ions having masses in the ratio 1:1 and charges 1:2 are projected into uniform magnetic field perpendicular to field with speeds in the ratio 2:3 the ratio of the radii of circular parts along which the two particles move is

When a sample of a radioactive nuclide decays, the count rate falls from 1200 to 150 in three minutes. What is the half-life of the radioactive nuclide?

A radioactive material has a half-life of 100s. If the initial amount of the material is 400 mg, then the amount left after 300s in mg is

The equation E = Pc is valid

Radioactive substance do not emit

The ratio of radius of 3^rd to 1^st Bohr’s orbit is

In photoelectric effect, which factor increases by increasing the intensity of incident photon?

The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series is

A beam of electron pass between the poles of a magnet as shown, the beam will be deflected

An electron of the hydrogen atom in the second orbit, is called its:

The momentum of a photon is 2×10⁻¹⁶gm-cm/sec. Its energy is

In compton effect an X-ray photon makes a collision with an electron of the scatterer. The electron is assumed to be initially

Two identical coaxial circular loops carry a current i each circulating in the same direction. If the loops approach each other, you will observe that the current in

What is the value of current in a wire of 1cm long at right angle to a uniform magnetic field of 0.5 Wb/m2. When the force acting on the wire is 5N.

SI unit of flux density is

For a pair production, the minimum frequency of the gamma ray must be

Various types of cancer are treated by

A transformer is used to light a 100W and 110V lamp from 220V mains. If the main current is 0.5 amp, the efficiency of transformer is approximately

Two conducting circular loops F and G are kept in a plane on either side of a straight current-carrying wire as shown in the figure below. If the current in the wire decreases in magnitude, the induced current in the loops will be