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Category: Physics Articles

When alpha particles are directed onto atoms in a thin metal foil, some make very close collisions with the nuclei of the atoms and are scattered at large angles. If an alpha particles with an initial kinetic energy of 5 MeV happens to be scattered through an angle of 180o, which of the following must have been its …

As shown in the picture, a ball of mass m, suspended on the end of a wire, is released from height h and collides elastically, when it is at its lowest point, with a block of mass 2m at rest on a frictionless surface. After the collision, the ball rises to a final height equal to …

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 …

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 …

In the spectrum of Hydrogen, what is the ratio of the longest wavelength in the Lyman series (nf = 1) to the longest wavelength in the Balmer series (nf = 2)? A. 5/27 B. 1/3 C. 4/9 D. 3/2 E. 3 (GR9677 #09) Solution: Rydberg formula: λvac = the wavelength of the light emitted in vacuum RH = Rydberg constant …

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. The electric potential at a point P, which is located on the axis of symmetry a distance x from the center of the ring, is given by A. Q / (4πɛ0x) B. Q / …

The capacitor shown in Figure 1 above is charged by connecting switch S to contact a. If switch S is thrown to contact b at time t = 0, which of the curve in Figure 2 above represents the magnitude of the current through the resistor R as a function of time? A. A B. B C. C …

A beam of neutral hydrogen atoms in their ground state is moving into the plane of this page and passes through a region of a strong inhomogeneous magnetic field that is directed upward in the plane of the page. After the beam passes through this field, a detector would find that it has been A. deflected …

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 …

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:- 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 …