Category: Physics Articles

Thermal Physics – Power

A 100-watt electric heater element is placed in a pan containing one liter of water. Although the heating element is on for a long time, the water, though close to boiling does not boil. When the heating element is removed, approximately how long will it take the water to cool by 1 degree Celsius? (Assume that …

Electromagnetism – Oscillation

Question 3-4: refer to a thin, nonconducting ring of radius R, as shown below, which has a charge Q uniformly spread out on it. A small particle of mass m and charge –q is placed at point P and released. If R ≫ x, the particle will undergo oscillations along the axis of symmetry with an angular frequency that …

Electromagnetism – Faraday’s law

The circuit shown is in a uniform magnetic field that is into the page and is decreasing in magnitude at rate of 150 tesla/second. The ammeter reads A. 0.15 A B. 0.35 A C. 0.50 A D. 0.65 A E. 0.80 A (GR9677 #02) Solution: V − IR − ɛ = 0 I = (V − ɛ)/R ɛ = − dΦ/dt = −AdB/dt Given: dB/dt = −150 t/s (minus …

Constants

TABLE OF INFORMATION (Printed in the test booklet) me = 9.11 × 10−31 kg e = 1.60 × 10−19 coulomb N0 = 6.02 × 1023 per mole R = 8.31 joules/(mole K) k = 1.38 × 10−23 joule/K = 1.38 ×  10−16 erg/K c = 3 × 108 m/s h = 6.63 × 10−34 Joule second = 4.1 × 10−15 eV.second ħ = h/2π ɛ0 = 8.85 × 10−12 coulomb2/(newton meter2)   μ0 = 4π × 10−7 weber /(ampere meter)   G = 6.67 × 10−11 meter3/(kilogram second2)   g = 9.80 …

Resistors

Resistors:- The component which is having ‘opposing force’ similar in many respects to mechanical friction is called a resistors. The symbol of resistors is, the opposing force of resistors is  called a ‘resistance’. The resistance is measured in ohms. In resistors they are of two groups 1) fixed, 2) variable. 1) Fixed resistors:- The most commonly …