List of practice Questions

The resistance in ohm in the four arms of wheatstone bridge are as follows. In which case the bridge is balanced ?
The resistance of an ideal voltmeter is
The resistivity of a material is inversely proportional to
The resistivity of alloy manganin is
The resistivity of semiconductors depends on :
The resistor $R_1$ dissipates power $P$ when connected to a generator. If a resistor $R_2$ is inserted in series with $R_1$ the power dissipated by $R_1$
The temperature coefficient of resistance ot a wire is $0.00125 \, per \, ^\circ C$. At 300 K temperature its resistance is $1?$. The resistance of the wire will be $2?$ at
The thermometric liquid used to measure upto $-100^{\circ} C$ is
The total positive charge in a glass of water containing 180 gm of water is approximately :
The voltage $V$ and current. $I$ graphs for a conductor at two different temperatures $T_1$ and $T_2$ are shown in the figure.
The relation between $T_1$ and $T_2$ is
To obtain maximum resistance by joining the given resistors, they should be grouped in
Two batteries of emf $\varepsilon_{1}$ and $\varepsilon_{2}\left(\varepsilon_{2}>\varepsilon_{1}\right)$i) and internal resistances $r_1$ and $r_2$ respectively are connected in parallel as shown in figure
Two concentric circular coils A and B have radii 25 cm and 15 cm and carry currents 10A and 15A respectively. A has 24 turns, and B has 18 turns. The direction of currents are in opposite order. The magnetic induction at the common centre of the codlis
Two resistors of resistances $R_{1}=\left(300 \pm3\right)\,\Omega$ and $R_{2}=\left(500 \pm4\right)\,\Omega$ are connected in series. The equivalent resistance of the series combination is
With increase in temperature the conductivity of
Which of the following is secondary cell?
Which of the following is NOT the name of a secondary cell ?
Which of the following is correct for $V$-$I$ graph of a good conductor ?
Which of the following $I$- $V$ graph represents ohmic conductors ?
A galvanometer of $ 50\,\Omega $ resistance has $25$ divisions. A current of $ 4\times {{10}^{-4}} $ A gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of $25\, V$, it should be connected with a resistance of
An electric motor runs on DC source of emf $200 \,V$ and draws a current of $10\, A$. If the efficiency be $40\%$, then the resistance of armature is
A current of $5 \,A$ is passing through a metallic wire of cross-sectional area $ 4\times {{10}^{-6}}{{m}^{2}} $ . If the density of charge carriers of the wire is $ 5\times {{10}^{26}} $ $ {{m}^{-3}}, $ the drift velocity of the electrons will be
A galvanometer of resistance $20\, \Omega$ is to be converted into an ammeter of range $1\, A$. If a current of $1\, mA$ produces full scale deflection, the shunt required for the purpose is
A wire of length $l$ and resistance $R$ is stretched to get the radius of cross-section $ \frac{r}{2} $ . Then the new value of $R$ is
A sphere has surface charge density $\sigma$. It is surrounded by a spherical shell. The surface charge density on the spherical shell is