Block is balanced in air. find angle alpha and bita ​

Three capacitors c1=20mf   c2=40mf   c3=50mf are connected in series .if no capacitor can sustain more than 50v ,then the maximum potential difference between the two terminals x and y is? ​

State two factors on which the potential energyof a body at a certain height above the ground depends​

An illuminated objecf lies at 1metre from a screen. a convex lens is used to form the image of object on the screen placed placed at 75 centimetre from the lens. find focal length and magnification.