Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

If a dielectric substance is introduced between the plates of a charged air-gap capacitor. The energy of the capacitor will

(a) Increase	(b) Decrease
(c) Remain unchanged	(d) First decrease and then increase

Electroscope is used:

The value of photoelectric current depends :

One conducting U tube can slide inside another as shown in figure, maintaining electric contacts between the tubes. The magnetic field B is perpendicular to the plane of the figure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v where l is the width of each tube, will be

A coil of wire of a certain radius has 100 turns and a self-inductance of 15 mH. The self-inductance of a second similar coil of 500 turns will be:

A circular loop is kept in that vertical plane which contains the north-south direction. It carries a current that is towards north at the topmost point. Let A be a point on the axis of the circle to the east of it and B a point on this axis to the west of it. The magnetic field due to the loop

In an A.C. circuit the voltage is V, and current is I, then power loss will be :

NOR gate is the series combination of:

A cube of a metal is given a positive charge Question: For this system, which of the following statements is true?