## What is proactive and retroactive interference?

Proactive interference (pro=forward) occurs when you cannot learn a new task because of an old task that had been learnt. Retroactive interference (retro=backward) occurs when you forget a previously learnt task due to the learning of a new task.

## What does it mean for two waves to be in phase?

What is Phase? Two sound waves of the same frequency that are perfectly aligned have a phase difference of 0 and are said to be “in phase.” Two waves that are in phase add to produce a sound wave with an amplitude equal to the sum of the amplitudes of the two waves.

## What is wave optical phase?

Phase is the same frequency, same cycle, same wavelength, but are 2 or more wave forms not exactly aligned together. “Phase is not a property of just one RF signal but instead involves the relationship between two or more signals that share the same frequency.

## What is the difference between in phase and out of phase?

In phase is when two sine functions have the same phase and period and so have the same peaks and troughs, even though they may be several periods off. That is, ϕ1=2kπϕ2 for k=0,1,2,3… and ω1=ω2. Similarly, out of phase is when the function is not in phase.

## What is in phase and out of phase?

If the crests of two waves pass the same point or line at the same time, then they are in phase for that position; however, if the crest of one and the trough of the other pass at the same time, the phase angles differ by 180°, or π radians, and the waves are said to be out of phase (by 180° in this case).

## Are stationary waves in phase?

Since adjacent points are in phase, no energy is transferred from one point to the next, unlike a travelling wave. Standing waves are formed by the superposition of two travelling waves of the same frequency (with the same polarisation and the same amplitude) travelling in opposite directions.

## What is a phase difference?

Phase Difference is used to describe the difference in degrees or radians when two or more alternating quantities reach their maximum or zero values. Previously we saw that a Sinusoidal Waveform is an alternating quantity that can be presented graphically in the time domain along an horizontal zero axis.

## What is the phase of a function?

In physics and mathematics, the phase of a periodic function of some real variable (such as time) is an angle-like quantity representing the number of periods spanned by that variable.

## How do you find the phase difference between two SHM?

- Phase difference: △ϕ=ϕ2−ϕ1.
- △ϕ=2π−6π
- △ϕ=63π−π=3π

## What is the phase of SHM?

Phase of a point in SHM is the angle made by the point, in uniform circular motion whose projection is that simple harmonic motion, with the initial point of motion at the centre of the circular motion or the mean position of the simple harmonic motion.

## What is phase constant in SHM?

The quantity φ is called the phase constant. It is determined by the initial conditions of the motion. If at t = 0 the object has its maximum displacement in the positive x-direction, then φ = 0, if it has its maximum displacement in the negative x-direction, then φ = π. The quantity ωt + φ is called the phase.

## What is PHI in SHM?

This is the generalized equation for SHM where t is the time measured in seconds, ω is the angular frequency with units of inverse seconds, A is the amplitude measured in meters or centimeters, and ϕ is the phase shift measured in radians (Figure 15.2.

## What are characteristics of SHM?

What are characteristics of SHM?

- In simple harmonic motion, the acceleration of the particle is directly proportional to its displacement and directed towards its mean position.
- The total energy of the particle exhibiting simple harmonic motion is conserved.
- SHM is a periodic motion.