Why is `I to V` characteristic of a solar cell draw in the fourth quadrant of the coordinate system?

The I- V characteristic of on LED is

Find coordinates of mass center of a quarter sector of a uniform disk of radius r placed in the first quadrant ofa Cartesian coordinate system with centre at origin.

The V to I characteristic of a silicon diode is shown in the figure. Calculate the resistance of the diode at (a) I_(D)=15mA and (b) V_(D)=-10V .

The V-I characteristic of a silicon diode is shown in the Fig. 14.17. Calculate the resistance of the diode at (a)I_(D) = 15 mA and (b) V_(B)=-10 V

Path traced by a moving particle in space is called trajectory of the particle. Shape of trajectiry is decided by the forces acting on the particle. When a coordinate system is associated with a particle motion, the curve equation in which the particle moves [y=f(x)] is called equation of trajectory. It is just giving us the relation among x and y coordinates of the particle i.e. the locus of particle. To find equation of trajectory of a particle, find first x and y coordinates of the particle as a function of time eliminate the time factor. In above the velocity (i.e. (dvec(r))/(dt)) at t=0 is :-

Path traced by a moving particle in space is called trajectory of the particle. Shape of trajectiry is decided by the forces acting on the particle. When a coordinate system is associated with a particle motion, the curve equation in which the particle moves [y=f(x)] is called equation of trajectory. It is just giving us the relation among x and y coordinates of the particle i.e. the locus of particle. To find equation of trajectory of a particle, find first x and y coordinates of the particle as a function of time eliminate the time factor. In above question initial acceleration (i.e. (d^(2)vec(r))/(dt^(2))) of particle is :-

Path traced by a moving particle in space is called trajectory of the particle. Shape of trajectiry is decided by the forces acting on the particle. When a coordinate system is associated with a particle motion, the curve equation in which the particle moves [y=f(x)] is called equation of trajectory. It is just giving us the relation among x and y coordinates of the particle i.e. the locus of particle. To find equation of trajectory of a particle, find first x and y coordinates of the particle as a function of time eliminate the time factor. The position vector of car w.r.t. its starting point is given as vec(r)=at hat(i)- bt^(2) hat(j) where a and b are positive constants. The locus of a particle is:-

An experiment is preformed to determine the I-V characteristics of a Zener diode, which has a protective resistance of R = 100 Omega , and maximum power of dissipation rating of 1 W. The minimum voltage range of the DC source in the circuit is :-