$A$ nichrome wire has a resistance of $10\, \Omega$. Find the resistance of another nichrome wire,whose length is three times and area of cross-section four times the first wire.

Draw a schematic diagram of an electric circuit (in the "on" position) consisting of a battery of five cells of $2\, V$ each, a $5\, \Omega$ resistor, a $8\, \Omega$ resistor, a $12\, \Omega$ resistor and a plug key, all connected in series. An ammeter is put in the circuit to measure the electric current through the resistors and a voltmeter is connected so as to measure the potential difference across the $12\, \Omega$ resistor.
Calculate the reading shown by the
$(a)$ ammeter
$(b)$ voltmeter in the given electric circuit.

State the factors on which the resistance of a cylindrical conductor depends. How will the resistance of a conductor change if it is stretched so that its length is doubled?

Two conductors,one having resistance $R$ and another $2R$ are connected in turn across a $dc$ source. If the rate of heat produced in the two conductors is $Q_{1}$ and $Q_{2}$ respectively,what is the value of $Q_{1} / Q_{2}$?

Who discovered the electron?

$1 \, \mu A = \ldots \ldots \ldots \, A$