Current Electricity - Electromagnetism - Physics Previous Year Questions

If voltage \(V=(200\pm 8)V\) and current \(I=(20\pm0.5)A\), then the percentage error in resistance R is

To the potentiometer wire of length L and 10\(\Omega\) resistance, a battery of emf 2.5 V and a resistance R are connected in series. If a potential difference of 1 V is balanced across L/2 length, the value of R in \(\Omega\) will be

Point out the right statements about the validity of Kirchhoff’s junction rule,

If \(P=Q=R=10\Omega\) and \(S=20\Omega\), then what resistance should be joined with S to balance the Wheatstone's network?

The resistance of a wire is R ohm. If it is melted and stretched to n times its original length, its new resistance will be

For the given electrical arrangement, what is the value of current I?

A cell of emf 2 V is connected with a load of resistance 1.5 \(\Omega\). The power delivered by the cell to the load is maximum, then power transferred to the load is

A galvanometer having a resistance of 4 \(\Omega\) is shunted by a wire of resistance 2 \(\Omega\). If the total current is 1.5 A, the current passing through shunt is

The electric flux from cube of side \(1 \mathrm{~m}\) is '\(\Phi\)' When the side of the cube is made \(3 \mathrm{~m}\) and the charge enclosed by the cube is made one third of the original value, then the flux from the bigger cube will be :

A resistor of wire \(24 \mathrm{~cm}\) length and resistance \(8 \Omega\) is stretched in to a uniform wire of \(48 \mathrm{~cm}\) length, then the new resistance will be :

The SI unit of electrical conductivity is :

The current drawn by the primary coil of an ideal transformer, which steps up \(22 \mathrm{~V}\) into \(220 \mathrm{~V}\), to operate a device having a load resistance \(110 \Omega\) is:

A battery is made of 12 cells having emf \(5 \mathrm{~V}\) each. If three cells are unknowingly connected wrong, the resultant emf of the battery will be:

The current passing through the 100\(\Omega\) resistor in the given electrical circuit is :

The current sensitivity of a galvanometer having 20 divisions is \(10 \mu \mathrm{A} /\) div. If the resistance of the galvanometer is \(100 \Omega\) then the value of the resistance to be used to convert this galvanometer in to an voltmeter to read up to \(1 \mathrm{~V}\) is :

The resistance of a wire at room temperature \(20^{\circ} \mathrm{C}\) is found to be \(10 \Omega\). If resistance of the wire increases by \(10 \%\), then the temperature of the wire will be (The temperature coefficient of the material of the wire is \(0.002 /{ }^{\circ} \mathrm{C}\))

The potential difference between the points \(\mathrm{P}\) and \(\mathrm{Q}\) of the arrangement shown in figure is

A storage battery of emf \(28.0 \mathrm{~V}\) and internal resistance \(0.5 \Omega\) is being charged by a \(140 \mathrm{~V}\) dc supply using a series resistor of \(27.5 \Omega\). The terminal voltage of the battery during charging is

A wire of uniform cross section and resistance 4 ohms is bent in the shape of square ABCD. Point A is connected to a point \(\mathrm{P}\) on DC by a wire AP of resistance \(1 \mathrm{ohm}\). When a potential difference is applied between \(\mathrm{A}\) and \(\mathrm{C}\), the points \(\mathrm{B}\) and \(\mathrm{P}\) are seen to be in same potential. What is the resistance of part \(\mathrm{DP}\) ?

An electron starting from rest and moving with the velocity \(\mathrm{v}\) through a potential difference \(\mathrm{V}\) is shown by the graphs below. Identify the correct graph.