Waves
the change in frequency of waves due to the relative motion of the wave source and the observer is called by
the doppler effect
the point on a stationary wave that has zero displacement (do not move) is called
node
what is meant by current?
the rate of flow of electric charge past a point
State Ohm’s law.
the p.d is directly proportional to the current at the constant temperature
It was the English scientist, ..., who suggested that the atom is a neutral particle made of a positive charge with lumps of negative charge (electrons) in it.
J. J. Thomson
the distance between two adjacent points on a wave oscillating in step with each other or distance between two adjacent peaks or troughs
A statement of the principle of superposition is?
“When two or more waves meet at a point, the resultant displacement is the algebraic sum of the displacements of the individual waves.”
the current I in a conductor is given by the equation shown: I = Anvq. What does the letter n representer in this equation?
number of charge carries per unit volume
state the Kirchoff's second law
the sum of the e.m.f. around any loop in a circuit is equal to the sum of the p.d. around the loop
State what is Leptons and Hadrons
Leptons is the particles that are unaffected by the strong nuclear force. Hadrons is the particles that are affected by the strong nuclear force.
State why light waves can be plane polarised but sound waves cannot
as light waves is transversal waves and sound waves is longitudinal waves
The air at the open end both at left and right side of the tube can vibrate most freely, so this are an antinode. Hence, the fundamental wave occurs when the length of the air column must be ... of a wavelength.
half
the characteristic I-V of filament lamp has the graph that not a straight line shows that the resistance of the lamp depends on ...
the temperature of its filament
According to potentiometer, there must be some point Y along the wire that, when touched by the jockey, gives zero deflection: there is ... current through its point.
no current
This means they are not very penetrative (they are absorbed by a thin sheet of paper) and have very short range (only a few centimetres in air). They is refer to ...
alpha particle
A wave from a source has an amplitude of 5.0 cm and an intensity of 400 W/m^2. The intensity of the wave is decreased to 100 W/m^2. Calculate the amplitude now.
2.5 cm
A diffraction grating can be used to split white light up into its component colours. This splitting of white light is known as
dispersion
A 1.0 m length of copper wire has a resistance of 0.50 Ω. What will be the resistance of a 1.0 m length of copper wire having half the diameter of the original wire?
2.0 Ω
The environmental conditions change causing a decrease in the resistance of the LDR. The temperature of the LDR remains constant. State whether there is a decrease, increase or no change to the intensity of the light illuminating the LDR?
increase
In addition to the β– particle, another lepton is emitted during the decay. State the name of the other lepton that is emitted.
anti-neutrino
Plane polarised light is incident at a Polaroid. Calculate the angle θ, which gives transmitted light of intensity 30% that of the incident intensity of light.
57o
A tuning fork that produces a note of 256 Hz is placed above a tube that is nearly filled with water. The water level is lowered until resonance is first heard. The length of the column of air above the water when resonance is first heard is 31.2 cm. Calculate the speed of the sound wave.
320 m/s
the p.d across the metal wire is kept constant. the length L and the diameter D of the wire are both varied. the type of metal is kept the same. How is the current in the wire related to L and D?
It is inversely proportional to L and directly proportional to D^2
To make a potentiometer, a driver cell of e.m.f. 4.0 V is connected across a 1.00 m length of resistance wire. A cell of unknown e.m.f. E is connected to the potentiometer and the balance point is found at a distance of 37.0 cm from the end of the wire to which the galvanometer is connected. Estimate the value of E.
1.48 volt
A hadron has a charge of –2e, where e is the elementary charge. State a possible quark composition for the hadron.
three up anti-quark