Jibananda Paul and Subrata Kumar Choudhury Solutions for Chapter: Current Electricity, Exercise 1: EXERCISE

State three differences between emf and terminal voltage of a cell.

Two bulbs rated as $60 \mathrm{W}$ and $100 \mathrm{W}$ are connected in series and parallel with same line voltage. In the two cases, which bulb glows more brightly than the other? Explain your answer.

State Lenz's law. How can Lenz's law be explained as a consequence of energy?

Write three important differences between AC generator and DC motor.

$90 \mathrm{J}$ of work is done in flowing $6 \mathrm{C}$ of positive charge between two points in an electric field. Find the potential difference between the two points.

$0.4 \mathrm{A}$ current flows through a bulb. If the bulb glows for three hours, how much electric charge is spent?

Calculate the heat given out by a filament of the bulb in $20 \sec$, when its resistance is $4 \mathrm{\Omega }$ and the potential difference across its ends is $12 \mathrm{V}$.

A family uses one $100 \mathrm{W}$ bulb, one $100 \mathrm{W}$ fan and a $1000 \mathrm{W}$ heater for $8 \mathrm{hours}$daily. Calculate the daily household bill, if one unit costs $\mathrm{Rs}. 3$.