A $4\,\mu F$ conductor is charged to $400\, volts$ and then its plates are joined through a resistance of $1\,k\Omega $. The heat produced in the resistance is ............... $J$
A$0.16$
B$1.28$
C$0.64$
D$0.32$
Medium
Download our app for free and get started
D$0.32$
d Heat produced = Energy stored in capacitor
$ = \frac{1}{2}C{V^2}$$ = \frac{1}{2} \times 4 \times {10^{ - 6}} \times {(400)^2}$$ = 0.32\,\,J$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
The supply voltage to room is $120\ V$. The resistance of the lead wires is $6\,\Omega$ . A $60\ W$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $240\ W$ heater is switched on in parallel to the bulb? ............. $V$
In the circuit shown, the reading of the Ammeter is doubled after the switch is closed. Each resistor has a resistance $1\,\Omega $ and the ideal cell has an $e.m.f.$ $10\, V$. Then, the Ammeter has a coil resistance equal to ............... $\Omega$
The given figure represents an arrangement of potentiometer for the calculation of internal resistance $(r)$ of the unknown battery $(E)$. The balance length is $70.0\, cm$ with the key opened and $60.0\,cm$ with the key closed. $R$ is $132.40 \Omega $. The internal resistance $(r)$ of the unknown cell will be.......$\Omega$ (Given $E_o > E$) :-
$STATEMENT-1$ In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. and
$STATEMENT-2$ Resistance of a metal increases with increase in temperature.
A steel wire has a resistance twice that of an aluminium wire. Both of them are connected with a constant voltage supply. More heat will be dissipated in
A cell $E _{1}$ of $emf 6 V$ and internal resistance $2 \Omega$ is connected with another cell $E _{2}$ of $emf 4 V$ and internal resistance $8 \Omega$ (as shown in the figure). The potential difference across points $X$ and $Y$ is............ $V$