CBSE Class 12 Current Electricity — practice questions
46 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 Current Electricity in the app →A bulb of resistance $240$ $\Omega$ is connected across $120$ V. Current through it is:A copper wire of length $L$ and area $A$ has resistance $R$. If length is doubled and area halved, the new resTwo resistors $3\ \Omega$ and $6\ \Omega$ are connected in parallel. The equivalent resistance is:A cell of EMF $1.5$ V and internal resistance $0.5\ \Omega$ delivers $1$ A to a bulb. Terminal voltage is:An electric current is constituted by:Materials that carry current when a field is applied are:The SI unit of resistance is the:Ohm's law states that V is proportional to:Doubling the length of a conductor makes its resistance:Halving the cross-section area of a conductor makes resistance:The resistance inside a cell itself is called its:Resistance is inversely proportional to the conductor's:The average time between electron collisions is called:The drift velocity of electrons points:Drift velocity is small compared with the electrons':Internal resistance of a cell may be neglected when it is:Compared with electrolytic cells, dry cells have internal resistance that is:Two cells joined can be replaced by one cell of equivalent:How many rules did Kirchhoff give for circuit analysis?Kirchhoff's junction rule for currents I1, I2 into a junction gives:The quantity denoted by sigma, the inverse of resistivity, is:Resistance depends on the material and on the conductor's:This chain deals with currents that are:If two identical slabs are joined end to end, the combined resistance is:Ohm's law was stated in the year:Ohm's law says the potential difference V equals:In the relation V equals RI, the constant R is called the:In the relation R equals rho l over A, the constant rho is the:Resistivity depends on the conductor's:The reciprocal of resistivity is called:Current per unit area normal to the current is called:The average time between electron collisions is called the:The average velocity of electrons under a field is called the:The surprising feature of drift velocity is that it is independent of:The drift velocity per unit electric field is called:The resistivity of a metallic conductor depends on its:The symbol alpha stands for the temperature coefficient of:The dimension of the temperature coefficient alpha is:Two resistors are in series if they share:Resistors are in parallel if one end of all of them is:Kirchhoff's junction rule concerns the sum of:At a junction, the current entering equals the current:The Wheatstone bridge is made up of how many resistors?In a Wheatstone bridge, the source is connected across the:Which device detects the current in a Wheatstone bridge?The resistance offered by the cell itself is called: