Exam Instructions for Science Paper

The electric field at a point outside a uniformly charged spherical shell is the same as if all the charge were concentrated at the center of the shell.

Gauss's Law relates the flux of the electric field through a closed surface to the enclosed charge.

The electric field inside a uniformly charged spherical shell is zero.

The drift velocity of electrons in a conductor is directly proportional to the electric field strength.

The drift velocity is inversely proportional to the length of the conductor.

The interference pattern in Young's double-slit experiment becomes narrower when the slits are brought closer together. This is because the path difference between the waves from the two slits is smaller, resulting in a more concentrated interference pattern.

The interference pattern in Young's double-slit experiment gets wider when the screen is moved further away from the slits. This is because the path difference between the waves from the two slits increases, causing the interference pattern to spread out.

The interference pattern in Young's double-slit experiment shifts towards the central maximum when red light is replaced with blue light. This is because blue light has a shorter wavelength than red light, leading to a smaller path difference and a shift in the pattern.

A virologist uses an electron microscope to study the details of a virus. Electron microscopes are capable of magnifying objects much more than light microscopes, allowing them to see tiny structures like viruses.

The work function of a photosensitive material is the minimum energy required to remove an electron from its surface. In the context of the provided graphs, the work function for M1 can be expressed as W1 = h * ν1, and the work function for M2 can be expressed as W2 = h * ν2, where h is Planck's constant, ν1 and ν2 are the threshold frequencies for M1 and M2 respectively, and e is the charge of an electron.

The energy difference between energy levels in an atom, typically measured in electron volts (eV).

The relationship between energy (E) and wavelength (λ) of light, given by: E = hc/λ, where h is Planck's constant and c is the speed of light.

The ability of a material to conduct electricity when a voltage is applied across it. It is the reciprocal of resistance.

A type of semiconductor diode that allows current to flow only in one direction. When forward biased, it has a low resistance and conducts current. When reverse biased, it has a high resistance and blocks current.

The current that flows through a circuit when the voltage across it is increased. In a forward biased diode, the current increases rapidly with increasing voltage.

The minimum energy required for an electron to transition from one energy level to another.

The wavelength of light that corresponds to the energy difference between two energy levels in an atom.

The rate at which photons are emitted from a source.

The voltage across a diode at which a significant increase in current occurs.

The small current flowing through a reverse-biased diode. It remains relatively constant despite changes in reverse voltage.

When the voltage applied across a diode is below a certain threshold, the current flow through the diode is negligibly small.

The resistance of a diode when it is forward-biased.

The resistance of a diode when it is reverse-biased.

The energy required to break apart the nucleus of an atom into its individual protons and neutrons. It is calculated by the difference in mass between the nucleus and its constituents.

The energy released when an atom undergoes fission, splitting into two or more lighter nuclei. It is calculated by the difference in mass between the reactants and products.

Rutherford's gold foil experiment led to the discovery of the nucleus. When alpha particles were fired at a thin gold foil, some were deflected at large angles, implying a dense, positively charged core within the atom.

The standard unit of atomic mass, defined as 1/12 the mass of a carbon-12 atom. It is used to express the masses of atoms and subatomic particles.

The energy equivalent of one unified atomic mass unit (u) is calculated using Einstein's famous equation E=mc², where c is the speed of light.

Atoms can absorb energy from external sources, causing their electrons to move to higher energy levels. This is called excitation.

When excited electrons in an atom return to their ground state (lowest energy level), they release energy in the form of photons, which are packets of light.

The lowest possible energy level of an electron in an atom. This is the state where the electron is most stable.

The resistance that needs to be connected in parallel with a galvanometer to convert it into an ammeter. It's calculated using the formula S = IgG/(I−Ig), where S is the shunt resistance, Ig is the galvanometer current, I is the total current, and G is the galvanometer resistance.

The process of adding a shunt resistance to a galvanometer to allow it to measure larger currents.

The magnetic field strength at the center of a circular coil carrying current is directly proportional to the current and the number of turns in the coil, and inversely proportional to the radius of the coil.

The magnetic field strength at an axial point on the axis of a circular coil carrying current is calculated using the formula B= (μ0 2NI(πa2))/(4π r3), where B is the magnetic field, μ0 is the permeability of free space, N is the number of turns, I is the current, a is the radius of the coil, and r is the distance from the center of the coil to the axial point.

The force exerted by a magnetic field on a moving charge is always perpendicular to both the magnetic field and the velocity of the charge. This force acts as a centripetal force, causing the charged particle to move in a circular path.