The actual value of resistance $R$, shown in the figure is $30\,\Omega $. This is measured in an experiment as shown using the standard formula $R = \frac{V}{I}$ where $V$ and $I$ are the readings of the voltmeter and ammeter, respectively. If the measured value of $R$ is $5\%$ less, then the internal resistance of the voltmeter is ................. $\Omega$
A$600$
B$570$
C$35$
D$350$
JEE MAIN 2019, Medium
Download our app for free and get started
B$570$
b $\frac{{30R}}{{R + 30}} = 30 \times 00.95$
$ \Rightarrow \,R = 570\,\Omega $
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.*
Suppose the drift velocity $v_d$ in a material varied with the applied electric field $E$ as ${v_d}\, \propto \,\sqrt E $ .Then $V - I$ graph for a wire made of such a material is best given by
A heating coil is labelled $100\, W$, $220\, V$. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is .............. $J$
As shown in the figure, a potentiometer wire of resistance $20\,\Omega$ and length $300\,cm$ is connected with resistance box (R.B.) and a standard cell of emf $4\,V$. For a resistance ' $R$ ' of resistance box introduced into the circuit, the null point for a cell of $20\,mV$ is found to be $60\,cm$. The value of ' $R$ ' is $.....\Omega$
The current density in a cylindrical wire of radius $4 \; mm$ is $4 \times 10^{6} \; Am ^{-2}$. The current through the outer portion of the wire between radial distance $\frac{R}{2}$ and $R$ is $\dots \; \pi A .$
Consider a $72\, cm$ long wire $AB$ as shown in the figure. The galvanometer jockey is placed at $P$ on $A B$ at a distance $x cm$ from $A$. The galvanometer shows zero deflection.
The value of $x,$ to the nearest integer, is ..... $cm$