Recent questions in Physics

Six lead-acid type of secondary cells each of emf 2.0 V and internal resistance 0.015 Ohm are joined in series to provide a supply to a resistance of 8.5 Ohm . What is the current drawn from the supply and its terminal voltage?
Answer : ### Given Data: * Number of cells, **n = 6** * EMF of each cell, **E_cell = 2.0 V** * Internal resistance of each cell, **r_cell = 0.015 Ω** * External resistance (load), **R = 8.5 Ω ... The current drawn from the supply is **1.40 A**. * The terminal voltage of the supply is **11.9 V**....

A storage battery of emf 8.0 V and internal resistance 0.5 Ohm is being charged by a 120 V DC supply using a series resistor of 15.5 Ohm . What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?
Answer : ### Given Data: * Electromotive force (emf) of the battery, $E = 8.0 \text{ V}$ * Internal resistance of the battery, $r = 0.5 \text{ } \Omega$ * DC supply voltage, $V_{supply} = ... to a much safer and more manageable **7.0 A**, protecting both the battery and the power supply from damage....

A silver wire has a resistance of 2.1 Ohm at 27.5 degree C , and a resistance of 2.7 Ohm at 100 degree C . Determine the temperature coefficient of resistivity of silver.
Answer : ### 1. Understand the Principle The relationship between resistance and temperature for most metals (like silver) over a moderate temperature range is approximately linear and can be described by the formula: $R_2 = ... 00394 °C⁻¹** Alternatively, in scientific notation: **α = 3.94 x 10⁻³ °C⁻¹**...

Three resistors 1 Ohm , 2 Ohm and 3 Ohm are combined in series. What is the total resistance of the combination?
Answer : When resistors are combined in series, the total resistance is the sum of the individual resistances. The formula is: R_total = R1 + R2 + R3 Given the values: * R1 = 1 Ω * R2 = 2 Ω * R3 = 3 Ω ... = 1 Ω + 2 Ω + 3 Ω = 6 Ω So, the total resistance of the combination is **6 Ohms**....

A battery of emf 10 V and internal resistance 3 Ohm is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?
Answer : ### Given Information: * **EMF of the battery (E):** 10 V * **Internal resistance (r):** 3 Ω * **Current in the circuit (I):** 0.5 A --- ### 1. What is the resistance of the ... text{V}$ Both methods give the same result. **Answer:** The terminal voltage of the battery is **8.5 V**....