Exams › NEET › Physics
A galvanometer having a coil resistance of 60 Ω shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents upto 5.0 amp by
- putting in series a resistance of 15Ω
- putting in series a resistance of 240Ω
- putting in parallel a resistance of 15Ω
- putting in parallel a resistance of 240Ω
Correct answer: putting in parallel a resistance of 15Ω
Solution
To convert the galvanometer into an ammeter, a shunt resistance is connected in parallel. The shunt resistance is calculated using the formula Rs = (Ig * Rg) / (I - Ig), where Ig is the galvanometer current, Rg is the galvanometer resistance, and I is the desired current. Substituting the values, Rs = (1 * 60) / (5 - 1) = 15Ω. Thus, a 15Ω resistance in parallel is required.
Related NEET Physics questions
- An alternating electric field, of frequency ν, is applied across the dees (radius = R) of a cyclotron that is being used to accelerate protons (mass = m). The operating magnetic field (B) used in the cyclotron and the kinetic energy (K) of the proton beam, produced by it, are given by:
- A proton carrying 1 MeV kinetic energy is moving in a circular path of radius R in uniform magnetic field. What should be the energy of an α-particle to describe a circle of same radius in the same field?
- A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
- An electron enters a region where magnetic field (\( \vec{B} \)) and electric field (\( \vec{E} \)) are mutually perpendicular, then
- A \( 10 \, \text{eV} \) electron is circulating in a plane at right angles to a uniform field at magnetic induction \( 10^{-4} \, \text{Wb/m}^2 \) (\( = 1.0 \, \text{gauss} \)). The orbital radius of the electron is
- A uniform magnetic field acts at right angles to the direction of motion of an electron. As a result, the electron moves in a circular path of radius \( 2 \, \text{cm} \). If the speed of electron is doubled, then the radius of the circular path will be
⚔️ Practice NEET Physics free + battle 1v1 →