Convex Lens Focal Length, Galvanometer Resistance & Wire Resistance
Aim: Convex Lens Focal Length
To find the focal length of a convex lens by plotting a graph:
- Between u and v
- Between 1/v and 1/u
Apparatus
An optical bench with three uprights, a convex lens, lens holder, two optical needles, a knitting needle, and a half-meter scale.
Formula Used
The relation between u, v, and f for a convex lens is: 1/f = 1/v – 1/u
Where:
- f: focal length of the convex lens
- u: distance of the object needle from the lens’ optical center
- v: distance of the image needle from the lens’ optical
Gothic Architecture: Cathedrals, Elements, and History
Gothic Architecture: Origins and Price
Gothic architecture originated in northern France in the early 12th century, succeeding the Romanesque tradition, and reached its perfection in the 13th century. A key element is the Gothic cathedral, which defines the appearance of the Gothic city. The cathedral is the spiritual symbol of the church, and its celestial nature is reflected through:
- Verticality: The cathedral’s vertical lines make man feel small in the face of its grandeur. This feeling is emphasized
Florence Cathedral Dome: Architecture and Symbolism
Florence Cathedral Dome: An Architectural Marvel
Understanding Noise and Vibration: Key Concepts
Noise
Noise: A wave that moves through air and water (partially elastic medium). We perceive it as sound pressure.
Sound Pressure and Levels
Sound Pressure Variations: Measured as Sound Pressure Level (SPL) in decibels (dB).
Pressure = Force / Area = Newton / meter2 = Pascal.
- Audible Field: To produce an auditory sensation, the frequency must be between 20 and 20,000 Hz.
- Pain Threshold: 120 dB, equivalent to 20 N/m2 = 20 Pa.
- Perception Threshold: 2 x 10-5 Pa, or 0 dB.
Sound Wave Characteristics
Sound Velocity:
Read MoreElectric Potential and Energy: Problems & Solutions
Electric Potential Energy Change: Electron in Thunderstorm
During a thunderstorm, the electric potential difference between a cloud and the ground is Vcloud – Vground = 1.3 x 108 V, with the cloud being at the higher potential. What is the change in an electron’s electric potential energy when the electron moves from the ground to the cloud?
Work Done by Electric Force on a Sodium Ion
Suppose that the electric potential outside a living cell is higher than that inside the cell by 0.070 V. How much
Kirchhoff’s Laws and Stellar Properties
Kirchhoff’s Laws
Kirchhoff’s Laws describe the behavior of light interacting with matter, resulting in different types of spectra:
- Law 1: Continuous Spectrum: A solid, liquid, or dense gas excited to emit light will radiate at all wavelengths, producing a continuous spectrum.
- Law 2: Emission Spectrum: A low-density gas excited to emit light will do so at specific wavelengths, producing an emission spectrum.
- Law 3: Absorption Spectrum: If light comprising a continuous spectrum passes through a cool,