Wave Optics — Physics STD 12 Science — Question

If a lens is cut into two pieces perpendicular to the principal axis and only one part is used, the intensity of the image

To get maximum current in a resistance of 3 ohms, one can use n rows of m cells (connected in series) connected in parallel. If the total number of cells is 24 and the internal resistance of a cell is 0.5 ohms then:

Longitudinal waves cannot:

1. Have a unique wavelength
2. Transmit energy
3. Have a unique wave velocity
4. Be polarized.

Two parallel wires carry currents of 20A and 40A in opposite directions. Another wire carying a current anti parallel to 20A is placed midway between the two wires. T he magnetic force on it will be:

1. Towards 20A.
2. Towards 40A.
3. Zero.
4. Perpendicular to the plane of the currents.

A photon, an electron and a uranium nucleus all have the same wavelength. The one with the most energy(a) Is the photon(b) Is the electron(c) Is the uranium nucleus(d) Depends upon the wavelength and the properties of the particle.

An element has number of proton = 7. Then what will be its atomic number?

Coulomb’s force between two stationery charges is also:

Two coils P and Q are lying parallels and very close to each other. Coil P is connected to an AC source whereas Q is connected to a sensitive galvanometer. On pressing key K.