definition of positive work

When q is acute, cos q is positive. Hence, the work done is positive. When a body falls freely under the force of gravity, q = 0, cos q = 1. Hence, the work done by gravity is positive. When a gas in a cylinder, fitted with a movable p..

Let us suppose that the generator coil ABCD is initially in the horizontal position. As the coil rotates in the anticlockwise direction between the pole N and S of the magnet the side AB of the coil moves down cutting the magnetic lines of force near the N-pole of the magnet and side DC m..

>From this it is found that when Zn is added to CuSO 4 solution, Zn displaces Cu from CuSO 4 with the liberation of heat. But in the electrochemical cell there is no direct contact between Zn and CuSO 4 . Hence whatever the heat energy that would have been liberated appears in the form of electrica..

To start with, suppose the plane of the coil is perpendicular to the plane of the paper in which the magnetic field is applied, with AB at the front and CD at the back, the flux linked with the coil is maximum in this position. As the coil rotates clockwise, AB moves inwards and CD moves..

The ray diagram given below gives the principle of a compound microscope. The object is mounted on the stand below the microscope tube. The objective lens forms a real, inverted and magnified image (I 1 ) of the object. The image I 1 acts as an object for the eye piece. The position of th..

Let us consider a situation where the force is acting along the X-axis and the magnitude of the force is varying with position 'x'. Thus, as the ball moves, the magnitude of the work done by the force, on the ball, changes. The adjacent graph shows the plot of a one dimens..

The V E E supply is used to forward bias emitter base junction. As a result significant current flows, once the potential barrier is exceeded. The majority charge carriers diffuse from emitter into base and this results in emitter current I E as indicated in the above diagram. Once these reach the ..

>A metal contains a large number of free electrons. They move at random within the metal with different velocities. But at ordinary temperatures, they cannot leave the surface due to attractive forces between the electrons and the positive ions. If the metal is heated, the kinetic energy ..

(i.e., the magnitude and the direction of the force do not change.). Work is the energy transferred to or from an object by means of a force acting on the object. Energy transferred to the object is positive work and energy transferred from the object is negative ..

When the body is at position C, its height above the ground may be regarded as zero. Therefore, potential energy of the body = 0. If v c is the velocity with which the body touches the ground, then v c 2 - 0 = 2gh v c 2 = 2gh Total energy of the body = mgh From the above illust..