3) a cathode ray tube (crt) is a device that produces a focused beam of electrons in a vacuum. the electrons strike a phosphor-coated glass screen at the end of the tube, which produces a bright spot of light. the position of the bright spot of light on the screen can be adjusted by deflecting the electrons with electrical fields, magnetic fields, or both. although the crt tube was once commonly found in televisions, computer displays, and oscilloscopes, newer appliances use a liquid crystal display (lcd) or plasma screen. you still may come across a crt in your study of science. consider a crt with an electron beam average current of 25.00î¼a. how many electrons strike the screen every minute?

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

no sign of dia of fuel cell

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.