2. A solid is rigid and cannot be compressed easily. Reason: Molecules are closely spaced and the intermolecular separation is very small which cannot be reduced further. 3. A solid does not diffuse into another solid easily. Reason: Intermolecular force of attraction is very strong. 4. A solid does not flow and can be stored in a container. Reason: Intermolecular fore of attraction is so strong that molecules do not flow and leave the surface of the solid. 5. A solid on hating usually changes into its liquid state.
To PWM, or not to PWM, That is the Question. Pulse width modulation (PWM) is a fancy term for describing a type of digital signal. Pulse width modulation is used in a variety of applications including sophisticated control circuitry. A common way we use them here at SparkFun is to control dimming of RGB LEDs or to control the direction of a servo motor.
Given a sufficient bandwidth, any analog value can be encoded with PWM. Figure 1 shows three different PWM signals. Figure 1a shows a PWM output at a 10% duty cycle. That is, the signal is on for 10% of the period and off the other 90%. Figures 1b and 1c show PWM outputs at 50% and 90% duty cycles, respectively. These three PWM outputs encode three different analog signal values, at 10%, 50%, and 90% of the full strength.