tick the correct answer

The resistance R of a conductor depends on its......................
1. length l
2. cross-sectional area A
3. both (i) and (ii)
4. none of these
................. is a property of the material and depends on temperature and pressure.
1. resistivity
2. current
3. charge
4. none of these
Current density j gives the amount of ................flowing per second per unit area normal to the flow
1. current
2. charge
3. resistivity
4. none of these
Ohm’s law is obeyed by many substances, but it is not a fundamental
law of nature. It fails if
1. V depends on I non-linearly
2. the relation between V and I depends on the sign of V for the same
  absolute value of V
3. The relation between V and I is non-unique.
4. all of the above
Total resistance R of n resistors connected in series is given by
1. R= Rp + Rs
2. 1/R = 1 /R1 + 1/R2 +........+ 1/Rn
3. R = R1 + R2 +..... + Rn
4. none of these
in kirchhoff junction rule : At any junction of circuit elements, the sum of currents entering the junction must ..................the sum of currents leaving it.
1. higher
2. equal
3. lower
4. none of these
in kirchhoff Loop Rule: The algebraic sum of changes in potential around any
closed loop must be
1. zero
2. one
3. two
4. three
The potentiometer is a device to compare ...............
1. emf
2. current
3. potential differences.
4. none of these
what is the dimension of electric field
1. [M L T–3 A–1]
2. [M LT-1A-3]
3. [M L]
4. none of these
which graph represent the resistivity of copper
4. none of these
in resister colour code what is the number of grey
1. 5
2. 8
3. 1
4. 9
in resister colore code what is the number of brown
1. 1
2. 5
3. 8
4. 4
consider a current carrying wire current I in the shape of a circle . note that as the current progress along the wire , the direction of j changes in an exact manner . while die/ current / remain unaffected . the agent that is essentially responsible for is
1. source of emf
2. electric field produced by charges accumulated on the surface of wire
3. the charges just behind a given segment of wire which push them just the right way by repulsion
4. the charges ahead
two cells of emf approximately 5V and 10 V are to be accurately compared using potentiometer of length 400 cm
1. the battery that runs the potientiometer should have voltage of 8V
2. the battery of potentiometer can have a voltage of 15 V and R adjust so that the potential drop access the wire slightly exceeds 10 V
3. the first portion of 50 cm of wire itself should have a potential drop of 10V
4. potentiometer is usually used for comparing resistamce and not voltage
which of the following is wrong ? resistivity of a conductor is
1. independent of tempertaure
2. inversely propotional to temperature
3. independent of dimension of conductor
4. less than resistivity of semiconductor
for measurement of potetial difference a potentiometer is preferred over voltmeter because
1. it is more sensitive than voltmeter
2. the resistance of potntiometer is less than voltmeter
3. potentiometer is cheaper than voltmeter
4. potentiometer does not take current from the circuit
when there is a electric current through a conducting wire along its length , then an electric field must exist
1. outside the wire but normal to it
2. outside the wire but parallel to it
3. inside the wire but parallel to it
4. inside the wire but normal to it
a charge is moving across a junction then
1. momentum will be conserved
2. omentum will not be conserved
3. at some places momenturii will be conserved and at some other places momentum will not be conserved
4. none of these
the resistivity of alloy manganin is
1. nearly independent of temperature
2. increase rapidly with increase in temperature
3. decrease with increase in temperature
4. increase rapidly with decrease in temperature
an electric heater is connected to the voltage supply . after few seconds current gets into steady value then its initial current will be
1. equal to its steady current
2. slightly higher than its steady current
3. slightly less than its steadiy current
4. zero
in the series combination of two or more than two resistances
1. the current through eah resistance is same
2. the voltage through the each resistance is same
3. neither current nor voltage through each re resistance is same
4. both current and voltage through each resistance are same
in parallel combination of n cells we obtain
1. more voltage
2. more current
3. less voltage
4. less current
combine three resistors 5Q , 4.5Q and 3Q in such a way that he total resistance of this combination is maximum
1. 12.5Q
2. 13.5 Q
3. 14.5Q
4. 16.5Q
in a wheatsone bridge if the battery and galvanometer are interchanged then the deflection in galvanometer will
1. change in previous direction
2. not change
3. change in opposite direction
4. none of these
when a metsl conductor connected to left gap of a meter bridge is heated , the balancing point
1. shift towards right
2. shift towards left
3. remains unchanged
4. remains at zero
in a potentiometer of 10 wire , the balancing point is obtained on the 7 th wire to shift the balance point to 9th wire we should
1. decrease resistance in the main circuit
2. increase resistance in the main circut
3. decrease resistance in series with the cell whose emf is to be measured
4. increase resistance in series with the cell whose ef to be determine
a Daniel cell is balanced on 125 cm length of a potentiometer wire now the cell is shot circuited by a resistance of 2ohm and the balance is obtained at 100 cm . the internal resistance of the daniel cell is
1. 0.5 ohm
2. 1.5 ohm
3. 1.25 ohm
4. 4/5 ohm
drift velocity vd varies with the intensity of electric field as per the relation
1. vd $\infty$ E
2. vd $\infty$ 1/E
3. Vd = constant
4. vd $\infty$ E2
the I-V charcteristic shown in figure represents
1. ohmic conductor
2. non-ohmic conductor
3. insulator
4. superconductor
the resistivity of alloy manganin is
1. nearly independent on temperature
2. increases rapidly with increase in temperature
3. decrease with increase in temperature
4. increase rapidly with decrease in temperature

tick the correct answer

Quiz