Narendra Kumar Solutions for Chapter: Electricity, Exercise 7: Test Your Self Exercise 2

A student sets up her circuit, for finding the equivalent resistance of two resistors $R_1$ and $R_2$ in series, in the manner as shown. She did not obtain the correct result in her experiment because of a mistake in her circuit. What mistake did she commit and what should be done to correct this mistake?

An ammeter can measure current up to $500 \mathrm{mA}$. There are 20 equal divisions between $0$ and $100 \mathrm{A}$ marks on its scale. During an experiment to determine the equivalent resistance of the two resistors joined in parallel a student observes ammeter’s pointer at 3rd graduation mark after zero when the key is off and the pointer at the 17th graduation mark after $200 \mathrm{mA}$ when the key is inserted into the plug. The correct value of the current flowing in the circuit is.

What are the main advantages of parallel circuits in domestic wiring?

Define kilowatt-hour. How is it related to joule?

Calculate the resistance of a bulb rated $100 \mathrm{W}$, $250 \mathrm{V}$.

Calculate the equivalent resistance between the points $A$ and $B$ in the given figure.

Calculate the energy released by a heater, which draws a current of $5 \mathrm{A}$ at $200 \mathrm{V}$ for $3$ minutes.