Class 12th

In a parallel plate capacitor set up, plate area of capacitor is 2 m² and the plates are separated by 1m. If the space between the plates are filled with a dielectric material of thickness 0.5 m and area 2 m² (See fig) the capacitance of the set-up will be ______ ε₀. (Dielectric constant of the material = 3.2) (Round off to the Nearest Integer)

A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75m. The wavelength (in meter) of the signal transmitted by this antenna would be

A resistor develops 500J of thermal energy in 20 s when a current of 1.5A is passed through it. If the current is increased from 1.5 A to 3 A, what will be the energy developed in 20 s.

A conducting bar of length L is free to slide on two parallel conducting rails as shown in the figure. Two resistors R1 and R2 are connected across the ends of the rails. There is a uniform magnetic field $\stackrel{}{}$ pointing into the page. An external agent pulls the bar to the left at a constant speed v.

The correct statement about the directions of induced currents I1 and I2 flowing through R1 and R2 respectively is:

For the given circuit, comment on the type of transformer used.

Find out the surface charge density at the intersection of point x = 3 m plane and x-axis, in the region of uniform line charge of 8 nC/m lying along the z-axis in free space.

A bar magnet of length 14 cm is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of 18 cm from the centre of the magnet. If BH = 0.4G, the magnetic moment of the magnet is 1G = 10^-4T

The stopping potential in the context of photoelectric depends on the following property of incident electromagnetic radiation:

The refractive index of converging lens is 1.4. What will be the focal length of this if it is placed in a medium of same refractive index? Assume the radii of curvature of the faces of lens are R₁ and R₂ respectively.

The de Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100V. What should be the ratio of their wavelengths? (m? = 1.00727u, m? = 0.00055u)