AKU MBBS Admission Test Physics Syllabus

Define angular velocity and relate it to linear velocity.

Angular velocity omega = theta/t (rad/s) is the rate of change of angular displacement. Linear (tangential) velocity v = r omega, where r is the radius.

Define torque and write its formula.

Torque (moment of force) is the turning effect of a force: tau = r F sin(theta) = r × F. SI unit is N·m. It causes angular acceleration.

Define moment of inertia and state its role in rotational motion.

Moment of inertia I = sum of m r^2 is the rotational analogue of mass; it measures resistance to angular acceleration. Rotational form of Newton's second law: tau = I alpha.

State the law of conservation of angular momentum and define angular momentum.

Angular momentum L = I omega (= mvr for a point mass). In the absence of external torque, total angular momentum is conserved; e.g., a spinning skater speeds up when pulling arms in (I decreases, omega increases).

Define stress and strain and give the formula for Young's modulus.

Stress = force per unit area (F/A, in pascals). Strain = change in dimension/original dimension (dimensionless). Young's modulus Y = tensile stress/tensile strain = (F/A)/(delta L/L).

State Hooke's law for elastic materials.

Within the elastic limit, stress is directly proportional to strain (stress = constant × strain); equivalently, for a spring, force F = -kx, where k is the spring constant.

What do the elastic limit and yield point mean on a stress-strain curve?

The elastic limit is the maximum stress a material can endure and still return to its original shape. Beyond the yield point the material deforms permanently (plastically) and will not fully recover.

State the equation of continuity for fluid flow and what it expresses.

A1 v1 = A2 v2 (volume flow rate is constant for an incompressible fluid). It shows that fluid speed increases where the cross-sectional area decreases.

State Bernoulli's equation and the principle it expresses.

P + (1/2)rho v^2 + rho g h = constant along a streamline. It expresses conservation of energy in fluid flow: where speed is higher, pressure is lower.

Define viscosity and state Stokes' law for a sphere in a fluid.

Viscosity is a fluid's internal resistance to flow. Stokes' law: the drag force on a small sphere is F = 6 pi eta r v, where eta is viscosity, r the radius, v the velocity.

What is terminal velocity?

Terminal velocity is the constant maximum velocity reached by an object falling through a fluid when the net force is zero (weight balanced by drag plus buoyancy), so acceleration becomes zero.

Define simple harmonic motion (SHM) and give its defining equation.

SHM is oscillatory motion in which acceleration is directly proportional to displacement from the mean position and directed toward it: a = -omega^2 x. The restoring force F = -kx.

Give the formulas for the time period of a mass-spring system and a simple pendulum.

Mass-spring: T = 2 pi sqrt(m/k). Simple pendulum: T = 2 pi sqrt(L/g). Both are independent of amplitude (for small oscillations).

For SHM, where are velocity and acceleration maximum and minimum?

Velocity is maximum at the mean (equilibrium) position and zero at the extremes. Acceleration is maximum at the extremes and zero at the mean position.

Differentiate between transverse and longitudinal waves with examples.

In transverse waves particles vibrate perpendicular to the direction of propagation (e.g., light, water surface, string waves). In longitudinal waves particles vibrate parallel to propagation, forming compressions and rarefactions (e.g., sound waves).

State the wave equation relating speed, frequency, and wavelength.

v = f λ, where v is wave speed, f is frequency, and λ is wavelength. Period T = 1/f.

How does the speed of sound vary with the medium and temperature?

Sound travels fastest in solids, slower in liquids, slowest in gases. In a gas, speed increases with temperature (roughly proportional to the square root of absolute temperature); in air it is about 343 m/s at 20 degrees C.

Define resonance.

Resonance occurs when a system is driven at its natural frequency, causing the amplitude of oscillation to become maximum because energy transfer from the driver is most efficient.

State the formula for the fundamental frequency of a stretched string.

f = (1/2L) sqrt(T/mu), where L is the length, T is the tension, and mu is the mass per unit length. The fundamental has one antinode and nodes at both ends.

State the Doppler effect and what happens to observed frequency as a source approaches or recedes.

The Doppler effect is the apparent change in frequency due to relative motion between source and observer. Frequency increases (pitch rises) when they approach and decreases (pitch falls) when they recede.

Distinguish between heat and temperature.

Heat is the total thermal energy transferred between bodies due to a temperature difference (in joules). Temperature is the measure of the average kinetic energy of particles and determines the direction of heat flow (in kelvin/celsius).

Convert between Celsius and Kelvin, and give absolute zero.

K = degrees C + 273.15. Absolute zero is 0 K = -273.15 degrees C, the temperature at which molecular kinetic energy is minimum.

Give the formulas for linear, areal, and volumetric thermal expansion.

Linear: delta L = L0 alpha delta T. Areal: delta A = A0 (2 alpha) delta T. Volumetric: delta V = V0 (3 alpha) delta T, where alpha is the coefficient of linear expansion.

State the first law of thermodynamics.

The heat supplied to a system equals the increase in its internal energy plus the work done by the system: Q = delta U + W. It is a statement of conservation of energy.

State the second law of thermodynamics.

Heat cannot spontaneously flow from a colder body to a hotter body; equivalently, no engine can convert all absorbed heat into work (entropy of an isolated system tends to increase).

Give the formula for the efficiency of a Carnot engine.

Efficiency = 1 - T_cold/T_hot, where temperatures are in kelvin. Carnot efficiency is the maximum possible for an engine between two given temperatures.

State the postulates of the kinetic theory of gases (key assumptions).

Gas consists of many tiny molecules in constant random motion; molecular volume is negligible vs container; collisions are perfectly elastic; no intermolecular forces except during collisions; average kinetic energy is proportional to absolute temperature.

Relate the average translational kinetic energy of a gas molecule to temperature.

Average translational KE = (3/2)kT per molecule, where k is the Boltzmann constant and T is absolute temperature. This shows temperature is a measure of molecular kinetic energy.

State the laws of reflection of light.

1) The incident ray, reflected ray, and the normal at the point of incidence all lie in the same plane. 2) The angle of incidence equals the angle of reflection.

State Snell's law of refraction and define refractive index.

n1 sin(theta1) = n2 sin(theta2). The refractive index n = speed of light in vacuum/speed in medium = c/v; it measures how much a medium bends light.

Define total internal reflection and the critical angle.

Total internal reflection occurs when light travels from a denser to a rarer medium and the angle of incidence exceeds the critical angle, so all light reflects back. Critical angle: sin(theta_c) = 1/n (for medium to air).

Write the mirror/lens formula and the magnification formula.

1/f = 1/v + 1/u (lens and mirror, using sign convention). Magnification m = h_image/h_object = -v/u (lens) or m = -v/u for mirrors. For mirrors f = R/2.

Compare the images formed by convex and concave lenses.

A convex (converging) lens can form real, inverted images or, when the object is within the focal length, a virtual, magnified, upright image. A concave (diverging) lens always forms a virtual, upright, diminished image.

State the condition for constructive and destructive interference of light in terms of path difference.

Constructive interference (bright fringe): path difference = n λ. Destructive interference (dark fringe): path difference = (n + 1/2) λ, where n is an integer.

Give the fringe spacing formula for Young's double-slit experiment.

Fringe spacing (separation between adjacent bright fringes) = λ D/d, where λ is wavelength, D is the slit-to-screen distance, and d is the slit separation.

Define diffraction and give the diffraction grating equation.

Diffraction is the bending and spreading of waves around obstacles or through narrow slits. Grating equation: d sin(theta) = n λ, where d is the grating spacing and n the order of the maximum.

State the magnifying power of a simple microscope (magnifying glass) at near point.

Magnifying power M = 1 + D/f, where D is the least distance of distinct vision (about 25 cm) and f is the focal length of the lens.

Describe a compound microscope and a telescope in terms of their lenses.

A compound microscope uses two convex lenses (objective of short focal length, eyepiece) to magnify small nearby objects. A refracting telescope uses a long-focal-length objective and a short-focal-length eyepiece to view distant objects; its magnification M = f_objective/f_eyepiece.

State Coulomb's law of electrostatics.

The force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them: F = k q1 q2 / r^2, where k = 1/(4 pi epsilon0) ≈ 9 × 10^9 N·m^2/C^2.

Define electric field intensity and electric potential.

Electric field intensity E = F/q (force per unit positive charge, in N/C or V/m), a vector. Electric potential V = W/q (work done per unit charge to bring it from infinity, in volts), a scalar; E = -dV/dr.

Define capacitance and give the capacitance of a parallel-plate capacitor.

Capacitance C = Q/V (charge stored per unit potential difference, in farads). For a parallel-plate capacitor C = epsilon0 epsilon_r A/d, where A is plate area, d the separation, and epsilon_r the relative permittivity of the dielectric.