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
Mention the important considerations required while fabricating a p-n junction diode to be used as a Light Emitting Diode (LED). What should be the order of band gap of an LED if it is required to emit light in the visible range?
Prove that the magnitude of electric current in a circuit is proportional to the drift velocity of free electrons. Verify Ohm's law with the help of drift velocity.
Draw a propagation diagram of a linearly polarized electromagnetic wave and write any two characteristics of electromagnetic wave.Magnitude of magnetic field associated with an electromagnetic wave in vacuum is $B_0=50 \times 10^{-8} T$. Write the magnitude of electric field associated with the wave in volt/meter
→Would the Bohr formula for the H-atom remain unchanged if proton had a charge (+4/3)e and electron a charge (-3/4)e, where e = 1.6 × 10-19C. Give reasons for your answer?
A thin metallic spherical shell of radius R carries a charge Q on its surface. A point charge Q/2 is placed at the centre C, and another charge + 2Q is placed outside the shell at A at a distance x from the centre as shown in the figure.
- Find the electric flux through the shell.
- State the law used.
- Find the force on the charges at the centre C of the shell and at the point A.
Accepting the relation $\frac{v_s}{v_p}=\frac{ N _s}{N_s}$ for ideal transformer, and using thé formula of power; derive
$\frac{I_p}{I_s}=\frac{v_s}{v_p}=\frac{N_s}{ N _p}$ and from that explain the types of the transformers.
→$\frac{I_p}{I_s}=\frac{v_s}{v_p}=\frac{N_s}{ N _p}$ and from that explain the types of the transformers.
A 12.3 eV electron beam is used to bombard gaseous hydrogen at room temperature. Upto which energy level the hydrogen atoms would be excited?
Calculate the wavelengths of the second member of Lyman series and second member of Balmer series.
Calculate the wavelengths of the second member of Lyman series and second member of Balmer series.
A hollow sphere of radius R lies on a smooth horizontal surface. It is pulled by a horizontal force acting tangentially from the highest point. Find the distance travelled by the sphere during the time it makes one full rotation.
A hypothetical magnetic field existing in a region is given by $\overrightarrow{\text{B}}=\text{B}_0\overrightarrow{\text{e}}_\text{r},$ where $\overrightarrow{\text{e}}_\text{r}$ denotes the unit vector along the radial direction. A circular loop of radius a, carrying a current i, is placed with its plane parallel to the x-y plane and the centre at (0, 0, d). Find the magnitude of the magnetic force acting on the loop.
→Two small bodies of masses 2.00kg and 4.00kg are kept at rest at a separation of 2.0m. Where should a particle of mass 0.10kg be placed to experience no net gravitational force from these bodies? The particle is placed at this point. What is the gravitational potential energy of the system of three particles with usual reference level?