Current electricity practice · Medium

As the temperature rises the resistance offered by metal

What determines the emf between the two metals placed in an electrolyte?

When a current passes through the junction of two different metals, evolution or absorption of heat at the junction is known as

The drift velocity of the electrons in a current carrying conductor is of the order of:

A $100\,\,watt$ bulb working on $200\,\,volt$ and a $200\,\,watt$ bulb working on $100\,\,volt$ have

An ammeter with internal resistance $90\,\,\mathrm{\Omega }$ reads $1.85\,\,A$ when connected in a circuit containing a battery and two resistors $700\,\,\mathrm{\Omega }$ and $410\,\,\mathrm{\Omega }$ in series. Actual current will be

A thermocouple is formed by two metals $X$ and $Y$, metal $X$ comes earlier to $Y$ in Seebeck series. If temperature of hot junction increases beyond the temperature of inversion, then direction of current in thermocouple will be from

The tolerance level of a resistor with the colour code red, blue, orange, gold is

Which of the following relation is wrong?

A potential difference ${V}$ is applied to a copper wire of diameter $d$ and length $L$. There will be no effect on the electron drift speed after doubling which of the parameter

Two identical cells send the same current in $3\,\,\Omega$resistance, whether connected in series or in parallel. The internal resistance on the cell should be

Two electric bulbs, one of $200\,\,volt\,\,40\,\,watt$ and the other $200\,\,volt\,\,100\,\,watt$ are connected in a house wiring circuit

The resistance of a metal increases with increasing temperature because

Emf of lead accumulator after complete charging is

By using only two resistances coils-singly, in series or in parallel one should be able to obtain resistance of $\mathrm{3,4,12 }\,\mathrm{and }\,\mathrm{16 }\,\mathrm{ohm}$. The separate resistance of the coil are

There are two electric bulbs of $40\,\,W$ and $100\,\,W$. Which one will be brighter when first connected in series and then in parallel

Pick out the wrong statement

Two bulbs rated $\left( {25\,\,w - 220\,\,v} \right)$ and $\left( {100\,\,w - 220\,\,v} \right)$ are connected in series to $440\,\,v$ time. Which one likely to fuse?

The current in a conductor varies with time $t$ as $I = 2t + \,\,3{t^2}$ where $I$ is in ampere and $t$ in seconds. Electric charge flowing through a section of the conductor during $t = 2\,\,\sec$ to $t = 3\,\,\sec$ is

A potentiometer wire of length $1\,\,m$ and resistance $10\,\,\mathrm{\Omega }$ is connected in series with a cell of $emf\,\,2\,\,V$ with internal resistance $1\,\,\mathrm{\Omega }$ and a resistance box including a resistance $R.$. If potential difference between the ends of the wire is $1\,\,mV$, the value of $R.$ is

A $25\,\,W,\,\,220\,\,V$ bulb and a $100\,\,W,\,\,220\,\,V$ bulb are connected in parallel across a $440\,\,V$ line

$\mathrm{160}\,\,\mathrm{W - }\,\mathrm{60}\,\,\mathrm{V}$ lamp is connected at $\mathrm{60}{\mkern 1mu} \mathrm{V}\,\,\,\mathrm{DC}$ supply. The number of electrons passing through the lamp in $\mathrm{1}\,\,\mathrm{min}$ is (the charge of electron $e = 1.6\,\, \times \,\,{10^{ - 19}}\,\,\mathrm{C}$

There are two electric bulbs rated $60 \mathrm{~W}, 120 \mathrm{~V}$ and $90 \mathrm{~W}$, $120 \mathrm{~V}$. They are connected in parallel with $240 \mathrm{~V}$ supply, then

A 2 volt battery, a $15\mathrm{ }\Omega$ resistor and a potentiometer of 100 cm length, all are connected in series. If the resistance of potentiometer wire is $5\mathrm{ }\Omega$, then the potential gradient of the potentiometer wire is

It is easier to start a car engine on a hot day than on a cold day. This is because the internal resistance of the car battery

A student has $\mathrm{10}\,\,\mathrm{resistors}$ of resistance $'r'$. The minimum resistance made by him from given resistors is

The electric intensity $E$, current density $j$ and specific resistance $k$ are related to each other by the relation

When a metal conductor connected to the left gap of a meter bridge is heated, the balancing point

A capacitor is connected to a cell of emf $E$ having some internal resistane $r$. The potential difference across the

For a metallic wire, the ratio $\frac{V}{i}(V =$ applied potential difference and $i$ =current flowing ) is