Lakhmir Singh and Manjit Kaur Solutions for Chapter: Electricity, Exercise 37: Short Answer Type Questions

Why is an electric light bulb not filled with air? Explain why argon or nitrogen is filled in an electric bulb.

Explain why, tungsten is used for making the filaments of electric bulbs.

Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.

When a current of $4.0 \mathrm{A}$ passes through a certain resistor for $10 \mathrm{minutes}, 2.88\times {10}^4 \mathrm{J}$ of heat is produced. Calculate:
(a) the power of the resistor.
(b) the voltage across the resistor.

A heating coil has a resistance of $200 \mathrm{\Omega }$. At what rate will heat be produced in it when a current of $2.5 \mathrm{A}$ flows through it? 

An electric heater of resistance $8 \mathrm{\Omega }$ takes a current of $15 \mathrm{A}$ from the mains supply line. Calculate the rate at which heat is developed in the heater.

A resistance of $25 \mathrm{\Omega }$ is connected to a $12 \mathrm{V}$ battery. Calculate the heat energy in $\mathrm{joules}$ generated per $\mathrm{minute}$.

$100 \mathrm{joules}$ of heat is produced per $\mathrm{second}$ in a $4 \mathrm{ohm}$ resistor. What is the potential difference across the resistor?