An electric fuse is a safety device that contains a wire designed to melt when the current exceeds a safe limit. This melting occurs due to the heat generated by the current, thereby breaking the circuit and preventing damage.
14682
What are the characteristic physical properties of a fuse wire used in electrical circuits?
A fuse wire is designed to protect electrical circuits from excessive current. It must have high resistance to generate sufficient heat when current exceeds the limit, and a low melting point so that it melts quickly to break the circuit, preventing damage to connected appliances.
14683
What is the technical term for the resistive coil used in heating appliances like electric room heaters or cooking stoves?
The heating component in appliances is commonly referred to as a heating element. It is typically made of a high-resistance alloy, such as nichrome, which generates heat via the Joule heating effect when current passes through it.
14684
Which of the following is not a recognized physical effect produced by an electric current?
Electric current produces several well-known effects: the magnetic effect (Oersted's discovery), the thermal effect (Joule heating), and the chemical effect (electrolysis). Contraction is not a standard physical effect caused by the flow of electricity.
14685
Why is tungsten the preferred material for the filament in an incandescent electric bulb?
Tungsten is used because it has a very high melting point (approximately 3422°C), allowing it to reach incandescence without melting. Its high resistivity ensures that it generates sufficient heat when current passes through it, producing light.
14686
What is the primary reason for transmitting electrical power over long distances at high voltages?
Power transmission at high voltages is used to reduce current for a given power level (P=VI). Since energy loss in transmission lines occurs due to resistive heating (I^2R), reducing the current significantly decreases these losses. This makes the transmission process much more efficient over long distances.
14687
A conductor has a potential difference of 7 V applied across it, resulting in a current of 2 A. Calculate the total energy dissipated in 2.5 minutes.
Energy is calculated as E = V * I * t. Given V = 7 V, I = 2 A, and t = 2.5 minutes (150 seconds), the calculation is E = 7 * 2 * 150 = 2100 Joules. This confirms that option C is the correct value for the energy consumed.
14688
What type of energy conversion occurs within a voltaic cell?
A voltaic or galvanic cell is an electrochemical device that utilizes a spontaneous chemical reaction to generate an electric current. The chemical potential energy stored in the reactants is converted into electrical energy as electrons flow through an external circuit from the anode to the cathode.
14689
What is the primary purpose of a fuse in an electric circuit?
An electric fuse is a safety device designed to protect electrical circuits from damage caused by excessive current, commonly known as overloading or short-circuiting. When the current exceeds a safe limit, the fuse wire melts due to heat, breaking the circuit and preventing potential fires or damage to appliances.
14690
What is the primary function of a fuse within a residential electrical circuit?
A fuse is a sacrificial safety component designed to protect electrical circuits from overcurrent conditions. It contains a metal wire or strip that melts when too much current flows through it, thereby breaking the circuit and preventing potential damage to wiring or appliances, as well as reducing the risk of electrical fires.
