211 SRI RAMAKRISHNA MISSION VIDYALYA POLYTECHNIC COLLEGE.

  Which motor is used in today's laser or inkjet printer? Most recent HP printers do not use stepper motors, but rather use DC motors that use external sensors for active positional feedback. These motors are designed to operate from 18-32V but can also run on 6 or 12V DC. To identify the DC motors, look for the two wires coming out of the motor. Stepper motor is identified as motors having more leads. It is employed for the movement of the cartridge. This to and fro movement is what enables ink application on the paper. The two types of stepper motors are unipolar and bipolar. Bipolar motors require a processor for precise control and are employed only in the high-end printer

  Betavolt , a Chinese startup, has announced that it has developed a revolutionary battery capable of powering smartphones for an impressive 50 years without requiring recharging. Termed as the world's first miniaturized atomic energy system, this  nuclear battery  utilizes 63 nuclear isotopes compactly arranged within a module smaller than a coin.

  Precautions in Connecting Booster Transformer The following precautions are to be taken while connecting a booster transformer in the traction circuit  1.  Booster transformer should be able to withstand severe mechanical stresses which will develop due the current of thousands of amperes under the conditions of short-circuit.   2.  Primary winding insulation of the booster transformer should be kept at 25 kV, while secondary winding insulation is kept at 3 kV because a high potential is created in the secondary winding under fault conditions. 3.  The booster transformer should not be located near the signals or the places where the train is likely to stop.

  Thin and flexible OLEDs are thinner than LEDs and can be made with flexible materials for foldable or rollable displays. Enhanced colour and contrast Individual OLED pixels generate their own light, improving colour and contrast control. OLEDs can acheive true blacks when the pixel is turned off. Fast response time OLEDs have a faster response time than LEDs. This means they can refresh faster, reducing motion blur and provide smoother transitions. Higher cost Fabricating OLED displays is more expensive than manufacturing LED displays. This higher cost is often passed on to consumers, making OLED-based devices pricier. Shorter lifespan OLEDs have a shorter lifespan than LED displays. The organic materials used in OLEDs can degrade over time, leading to colour and brightness issues.

 Comparison  Microprocessor Microcontroller Since memory and I/O are connected externally, the circuit becomes large in size. Since memory and I/O are present together, the internal circuit is small in size. It cannot be used in compact systems It can be used in compact systems. Cost is high Cost is low It is not suitable for devices that run on stored power since total power consumption is high due to external components. It can be used on devices that use stored power since total power consumption is low due to less external components. RAM, ROM, I/O units, and other peripherals are not embedded on a single chip. RAM, ROM, CPU and other peripherals are embedded on a single chip. Do not have power saving mode. Have a power-saving mode. Used in personal computers. Used in embedded systems. Less number of registers. More number of registers.  Uses an external bus. Uses an internal controlling bus. Based on the Von Neumann model Based on the Harvard architecture It is a central processin

  Self Inductance Definition:  When the current-carrying coil has the property of self-inductance, then it resists the change in the current flow is known as self-inductance.  This mainly occurs when the self-induced e.m.f is generated within  the coil . In other words, it can be defined as when the voltage induction occurs within a current-carrying wire. Self Inductance When the current increases or decreases, the self-induced e.m.f will resist the current.  Basically, the path of the induced e.m.f is reverse to the voltage applied, if the current is rising.  Similarly, the path of the induced  e.m.f  is in a similar direction to the applied voltage, if the flow of current is reducing.

  LDR Working Principle It works on the principle of photoconductivity whenever the light falls on its photoconductive material, it absorbs its energy and the electrons of that photoconductive material in the valence band get excited and go to the conduction band and thus increasing the conductivity as per the increase in light intensity. Also, the energy in incident light should be greater than the bandgap gap energy so that the electrons from the valence band got excited and go to the conduction band. The LDR has the highest resistance in dark around 1012 Ohm and this resistance decreases with the increase in Light. Light Intensity V/S Resistance As per the property of LDRs, the amount of light entering the LDR the inversely proportional to the resistance of the sensor, and the graph is hyperbolic in nature.