The more perpendicular the wires are to each other the induced current will be less.…
1. Incandescent light bulbs have a very thin filament that glows when hot. Thin filaments have very high / low resistance.…
* e. Knowing these relative quantities of heat, why is the temperature change of the cold water greater than the magnitude of the temperature change of the hot water.…
A voltage ΔV is applied across the ends of a nichrome heater wire having a cross-sectional area A and length L. The same voltage is applied across the ends of a second heater wire having a cross-sectional area A and length 2L. Which wire gets hotter? (a) the shorter wire, (b) the longer wire, or (c) more information is needed.…
1. Incandescent light bulbs have a very thin filament that glows when hot. Thin filaments have very / low resistance.…
The specific heat capacity of a substance is the amount of thermal energy required to heat one gram of that substance by one degree. It is an intensive property, as opposed to the heat capacity, which is an extensive property that depends on the amount of substance present. In this experiment, the heat capacity is determined by measuring the change in temperature of the cold water when a hot metal (that does not react with the water) is placed in it. It is assumed that the specific heat capacity is constant in the temperature range, although in reality it does vary with temperature.…
INTRODUCTION Electricity is usually invisible. Except for lightning and sparks, you never see it in daily life. However, light bulbs and a magnetic compass can show you when something electrical is happening. By observing their behavior and making a few assumptions, you can begin forming ideas about electricity. This type of thinking is called “building a model”. INVESTIGATION ONE: WHAT IS NEEDED TO LIGHT A BULB? 1.1 Activity: Lighting bulbs in a loop Insert three D-cells into the battery holder (as in Figure 1.1), and insert two ROUND bulbs (not long bulbs) into a pair of sockets. Use three wires to connect the sockets to each other and to the two “terminals” of the battery holder: 1) the spring inside the case near the red spot, and 2) the metal post on the outside of the case near the blue spot. The bulbs should light and be of similar brightness. The battery, bulbs and wires now form a “closed loop”.…
4. Increase the resistance (# green dots). What affect does this have on temperature? WHY?…
When someone touches one of the hot aluminum racks it no longer has to radiate to reach. He is in direct contact. Heat transfers better through a heat conductive medium. Most Metals transfer heat quickly. Since the human body consists mostly of water one can safely state that by touching a metal rack it is equivalent to boiling the water in the body.…
Apply concepts of temperature and heat as energy to solve problems concerning the transfer of heat and effects of heat on systems.…
Electricity is conducted through a conductor, in this case wire, by means of free electrons. The number of free electrons depends on the material and more free electrons means a better conductor, i.e. it has less resistance. For example, gold has more free electrons than iron and, as a result, it is a better conductor. The free electrons are given energy and as a result move and collide with neighbouring free electrons. This happens across the length of the wire and thus electricity is conducted. Resistance is the…
15. Explain why, when there is an electric current in a resistor, there is an energy transfer which heats the resistor…
The first objective of the measurement of thermal conductivity & one-dimensional heat conduction experiment was to identify three different metal specimens by comparing their experimentally determined thermal conductivities to known thermal conductivity values of existing metals. The second objective of the experiment was to establish a connection between the thermal conductivities & temperatures of the metal specimens. Thirdly, the contact resistance of the interfaces between the specimens was to be determined.…
1. Incandescent light bulbs have a very thin filament that glows when hot. Thin filaments have very HIGH resistance.…
Introduction: When an electrical potential exists in a circuit, a current may flow. Current is the flow of electrons in a circuit. Resistance in the circuit slows the flow of the electrons, reducing the current in the circuit. We will use the mathematical form of Ohm’s Law frequently when we investigate electric current and circuits later in this unit.…