Question
State the underlying principle of a potentiometer. Write two factors by which current sensitivity of a potentiometer can be increased. Why is a potentiometer preferred over a voltmeter for measuring the emf of a cell?
✓
Answer
Principle: The potential drop, across a part of a length l of a uniform wire of length L (L>l), is proportional to the length l.
Two factors:
Two factors:
- Increasing the length L of the wire.
- Connecting a suitable resistance, R, in series with the potentiometer wire.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Draw the graph to show variation of binding energy per nucleon with mass number of different atomic nuclei. Calculate binding energy/nucleon of $^{40}_{20}\text{Ca}$ nucleus.
Given:
mass of $^{40}_{20}\text{Ca} = 39.962589\text{u}$.
mass of proton $= 1.007825$ u.
mass of neutron $= 1.008665$ u.
and $1\ u = 931\ MeV/C^{2.}$
→Given:
mass of $^{40}_{20}\text{Ca} = 39.962589\text{u}$.
mass of proton $= 1.007825$ u.
mass of neutron $= 1.008665$ u.
and $1\ u = 931\ MeV/C^{2.}$
Calculate the number of states per cubic metre of sodium in 3s band. The density of sodium is $1013kg/ m^3$. How many of them are empty?
→Consider the situation shown in figure. What are the signs of $q_1$ and $q_2?$ If the lines are drawn in proportion to the charge, what is the ratio $\frac{\text{q}_1}{\text{q}_2}?$
→There are two sources of light A and B. The wavelength of light emitted from A is from $8000\mathring{\text{A}}$ to $11000\mathring{\text{A}},$ while that from B is from $3000\mathring{\text{A}}$ to $6000\mathring{\text{A}}.$ The intensity of A is 4 times that of B. But when light of A falls on metal, photoelectrons are not emitted whereas light of B can eject photoelectrons from the same metal. Explain its reason.
→A uranium reactor develops thermal energy at a rate of 300MW. Calculate the amount of $^{235}U$ being consumed every second. Average released per fission is 200MeV.
→A narrow beam of light passes through a slab obliquely and is then received by an eye. The index of refraction of the material in the slab fluctuates slowly with time. How will it appear to the eye? The twinkling of stars has a similar explanation.
If heavier bodies are attracted more strongly by the earth, why don't they fall faster than the lighter bodies?
A particle of mass m moves on a straight line with its velocity varying with the distance travelled according to the equation $\text{v}=\text{a}\sqrt{\text{x}},$ where a is a constant. Find the total work done by all the forces during a displacement from x = 0 to x = d.
→Explain the following:
- In the active state of the transistor, the emitter base junction acts as a low resistance while base collection region acts as high resistance.
- Output characteristics are controlled by the input characteristics in common emitter transistor amplifier.
- EDs are made of compound semiconductor and not by elemental semiconductors.
Explain how resistance of conductor depends on the dimension of the conductor and derive its equation.