Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
A potentiometer wire of length 1.0 m has a resistance of l5 $\Omega$. It is connected to a 5 V battery in series with a resistance of 5$\Omega$Determine the emf of the primary cell which gives a balance point at 60 cm.
Calculate the temperature at which the resistance of a conductor becomes 20% more than its resistance at 27°C. The value of the temperature coefficient of resistance of the conductor is $2.0 \times 10\frac{-4}{\text{K}}.$
A capacitor of capacitance $10\mu\text{F}$ is connected across a battery of emf 6.0V through a resistance of $20\text{k}\Omega$ for 4.0s. The battery is then replaced by a thick wire. What will be the charge on the capacitor 4.0s after the battery is disconnected?
Three resistors $2\ \Omega,\ 4\ \Omega\ \text{and}\ 5\ \Omega$ are combined in parallel. What is the total resistance of the combination?
If the combination is connected to a battery of emf 20 V and negligible internal resistance, determine the current through each resistor, and the total current drawn from the battery.
A resistance of $R \Omega$ draws current from a potentiometer as shown in the figure. The potentiometer has a total resistance $R_o\Omega$ . A voltage $V$ is supplied to the potentiometer. Derive an expression for the voltage across $R$ when the sliding contact is in the middle of the potentiometer.
Define the term ‘conductivity’ of a metallic wire. Write its SI unit.
Using the concept of free electrons in a conductor, derive the expression for the conductivity of a wire in terms of number density and relaxation time. Hence obtain the relation between current density and the applied electric field E.