Embibe Experts Solutions for Chapter: Current Electricity, Exercise 1: Kerala Board-2020

Write the unit of mobility.

The temperature dependence of resistivity of a material is shown below:

Identify the type of material.

The temperature dependence of resistivity of a material is shown below:

$\left(\mathrm{b}\right)$ Write the relation between resistivity and average collision time for electron.

The experimental set up to find an unknown resistance using a metre bridge is shown below:

$\left(\mathrm{a}\right)$ What is the working principle for a metre bridge?

The experimental set up to find an unknown resistance using a metre bridge is shown below:

$\left(\mathrm{b}\right)$ If the balance point is found to be at $39.5 \mathrm{cm}$ from the end $\mathrm{A}$, the resistor $\mathrm{S}$ is of $12.5 \mathrm{\Omega }$. Determine the resistance $\mathrm{R}$. Why are the connections between resistors in a metre bridge made of thick copper strips?

The experimental set up to find an unknown resistance using a metre bridge is shown below:

If the galvanometer and cell are interchanged at the balance point of the bridge, would the galvanometer show any current?

The transfer characteristic of $\mathrm{n}-\mathrm{p}-\mathrm{n}$ - transistor in $\mathrm{CE}$- configuration is shown in the figure.

A $\mathrm{CE}$ - transistor amplifier is shown in figure.

In this, the audio signal voltage across collector resistance of $2.0 \mathrm{K\Omega }$ is $2.0 \mathrm{V}$. Suppose the current amplification factor of the transistor is $100$. Then calculate the value of signal current through the base.

The transfer characteristic of $\mathrm{n}-\mathrm{p}-\mathrm{n}$, transistor in $\mathrm{CE}$- configuration is shown in the figure.

In the working of a transistor, the emitter-base $\left(\mathrm{EB}\right)$ - junction is forward biased while collector base $\left(\mathrm{CB}\right)$ - junction is reverse biased. Why ?