Kerala SSLC Physics flashcards
Kerala SSLC Physics · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Joule's law of heating
- Heat produced in a resistor equals I squared times R times t, where I is current in amperes, R is resistance in ohms and t is time in seconds.
- Electrical power formula
- Power consumed equals voltage multiplied by current, P = VI, and can also be written as I squared R or V squared divided by R.
- Electric fuse
- A thin wire of low melting point connected in series in the live wire; it melts and breaks the circuit when current exceeds its rated value.
- Short circuit
- A fault where live and neutral wires touch directly, lowering resistance sharply and allowing a dangerously large current to flow.
- One kilowatt-hour
- The commercial unit of electrical energy, equal to the energy used by a 1000 W appliance for one hour, that is 3.6 million joules.
- Right-hand grip rule
- Grip a straight conductor with the right hand, thumb pointing along the current; the curled fingers show the direction of the magnetic field lines.
- Solenoid magnetic field
- A current-carrying solenoid produces a nearly uniform magnetic field inside it and behaves like a bar magnet with north and south poles.
- Fleming's left-hand rule
- For a current-carrying conductor in a magnetic field: forefinger shows field, middle finger current, thumb the force on the conductor.
- Electromagnet
- A coil wound on a soft iron core that becomes magnetic only while current flows, so its magnetism can be switched on and off.
- Split-ring commutator
- A rotating contact that reverses the current direction in the coil every half turn, keeping the coil of a DC motor rotating continuously.
- Faraday's law of induction
- The emf induced in a coil is directly proportional to the rate of change of magnetic flux linked with the coil.
- Lenz's law
- The induced current flows in a direction that opposes the change in flux producing it, which is a consequence of conservation of energy.
- AC generator principle
- A coil rotated in a magnetic field experiences continuously changing flux, inducing an alternating emf delivered through slip rings.
- Transformer principle
- Mutual induction between two coils on a common core changes AC voltage; it cannot work with direct current because flux must change.
- Laws of reflection
- The angle of incidence equals the angle of reflection, and the incident ray, reflected ray and normal all lie in one plane.
- Mirror formula
- One divided by focal length equals one divided by image distance plus one divided by object distance, using the sign convention carefully.
- Refractive index
- The ratio of the sine of the angle of incidence to the sine of the angle of refraction, also equal to the speed of light in vacuum divided by that in the medium.
- Total internal reflection
- Occurs when light travels from a denser to a rarer medium at an angle of incidence greater than the critical angle, so it is fully reflected back.
- Concave mirror uses
- A converging mirror forming a real image beyond its focus; used in torch reflectors, headlights, dentist mirrors and solar cookers.
- Dispersion of white light
- Splitting of white light into its component colours because the refractive index of glass differs for different wavelengths, violet deviating most.
- Rayleigh scattering
- Scattering of light by particles much smaller than the wavelength, with intensity proportional to one over the fourth power of wavelength.
- Blue colour of sky
- Sunlight passing through the atmosphere is scattered by air molecules; shorter blue wavelengths scatter far more than red, reaching the eye from all directions.
- Red sunset explanation
- Near the horizon sunlight travels a long atmospheric path, so most blue light is scattered away and mainly red light reaches the observer.
- Wave equation
- Wave speed equals frequency multiplied by wavelength; frequency is the number of oscillations per second and its unit is the hertz.
- Longitudinal wave
- A wave in which particles of the medium vibrate parallel to the direction of propagation, forming compressions and rarefactions, as sound does in air.
- Audible range
- The range of frequencies a normal human ear can hear, from about 20 hertz to 20,000 hertz; higher frequencies are ultrasonic.
- Echo
- A sound heard again after reflection from a distant surface; it is distinct only if the reflecting surface is at least about seventeen metres away.
- Work done by a force
- Work equals force multiplied by displacement multiplied by the cosine of the angle between them; its SI unit is the joule.
- Kinetic energy
- The energy a body possesses due to its motion, equal to half its mass multiplied by the square of its speed.
- Law of conservation of energy
- Energy can be transformed from one form to another but cannot be created or destroyed; the total energy of an isolated system stays constant.
- Specific heat capacity
- The heat needed to raise the temperature of one kilogram of a substance by one kelvin; for water it is about 4200 joules per kilogram kelvin.
- Latent heat of fusion
- The heat required to change one kilogram of a solid to liquid at its melting point without any change in temperature.