Physics
The circuit depicted in the figure is employed for studying Ohm's Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes E1 & E2. He records the readings of the ammeter and voltmeter, thereby calculates the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills the tube 2.
Neglecting internal resistance of the cell use (> or < or =) to compare
(a) the resistance in both the cases.
(b) the voltmeter readings in both the cases.
(c) the specific resistance in both the cases.
Current Electricity
8 Likes
Answer
(a) As the resistance depends directly on length and inversely on area of the resistor and since here tube 2 is thicker and shorter than tube 1 thus, resistance of the tube 2 < resistance of the tube 1.
(b) The voltmeter reading for tube 1 is the same as the voltmeter reading for tube 2 because according to Ohm's law potential difference across a resistor depends only on the current applied not on the resistance of the resistor.
(c) As the specific resistance of a resistor is independent of its dimensions but depends only on the contained material and since here both tubes contain only mercury thus, the specific resistance in both the cases is the same.
Answered By
4 Likes
Related Questions
A person standing in front of a cliff fires a gun and hears its echo after 3s. If the speed of sound in air is 336 ms-1.
(a) Calculate the distance of the person from the cliff.
(b) After moving a certain distance from the cliff, he fires the gun again and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person moved.
The below picture shows a mother pushing her daughter sitting on a swing. The swing is going through the positions A, B, C where A and C are extreme positions and B is the mean position.
(a) Which is the right position i.e. at A, B or C, for the mother to give a constant periodic push to the swing every time in the forward direction to increase the amplitude of the swing?
(b) Name the phenomenon involved in this.
(c) Explain with this example how this phenomenon helps to increase the amplitude of the swing.
A radioactive nucleus X emits an alpha particle followed by two beta particles to form nucleus Y.
(a) With respect to the element X, where would you position the element Y in the periodic table?
(b) What is the general name of the elements X and Y?
(c) If the atomic number of Y is 80 then what is the atomic number of X?
Observe the given circuit diagram and answer the questions that follow :
(a) Calculate the resistance of the circuit when the key K completes the circuit.
(b) Calculate the current through 3 Ω resistance when the circuit is complete.