Download App

Moving Charges and Magnetism — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsMoving Charges and Magnetism5 Marks
Question
A multirange current meter can be constructed by using a galvanometer circuit as shown in Fig. We want a current meter that can measure 10mA, 100mA and 1A using a galvanometer of resistance 10Ω and that prduces maximum deflection for current of 1mA. Find S1, S2 and S3 that have to be used.

✓

Answer

Key concept: A galvanometer can be converted into ammeter by connecting a very low resistance wire (shunt S) connected in parallel with galvanometer. The relationship is given by IgG = (l - Ig) S, where Ig is the range of galvanometer, G is the resistance of galvanometer.

For measuring I1 = 10mA : IG.G = (I1 - IG)(S1 + S2 + S3)

For measuring I2 = 100mA : IG(G + S1) = (I2 - IG)(S2 - S3)

For measuring I3 = 1A : IG(G + S1 + S2) =(I3 - IG)(S3)

Gives S1 = 1Ω, S2 = 0.1Ω and S3 = 0.01Ω.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Long Answer Type Questions [5M]" from Moving Charges and Magnetism→Moving Charges and Magnetism — all question types→Physics STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

Derive the expression for the magnetic field at the site of a point nucleus in a hydrogen atom due to the circular motion of the electron. Assume that the atom is in its ground state and give the answer in terms of fundamental constants.
→
Distinguish the magnetic properties of dia, para- and ferro-magnetic substances in terms of (i) susceptibility, (ii) magnetic permeability and (iii) coercivity. Give one example of each of these materials. Draw the field lines due to an external magnetic field near a (i)diamagnetic, (ii) paramagnetic substance.
→
A body of mass 2kg is lying on a rough inclined plane of inclination 30°. Find the magnitude of the force parallel to the incline needed to make the block move:
  1. Up the incline
  2. Down the incline. Coefficient of static friction = 0.2.
→
Obtain the binding energy of the nuclei $^{56}_{26}\text{Fe }\text{ and }\ ^{209}_{83}\text{Bi}$ in units of MeV from the following data:
$\text{m}(^{56}_{26}\text{Fe})=55.934939\text{ u }$ $\text{ m}(^{209}_{83}\text{Bi})=208.980388\text{ u}$
→
Is it possible that in a Coolidge tube characteristic $\text{L}_\alpha$ X-rays are emitted but not $\text{K}_\alpha$ X-rays?
→
In en experiment on photoelectric effect, light of wavelength 400 run is incident on a cesium plate at the rate of 5.0W. The potential of the collector plate is made sufficiently positive with respect to the emitter so that the current reaches its saturation value. Assuming that on the average one out of every 10° photons is able to eject a photoelectron, find the photocurrent in the circuit.
→
What is meant by forward bias and reverse bias of p-n junction diode? Draw experimental electrical circuit diagram to study V-I characteristic in forward bias and reverse bias of p-n junction diode. Draw forward bias and reverse bias V-I characteristic curves of p-n junction diode and briefly explain the following :
(i) Threshold or cut-in voltage
(ii) Breakdown voltage.
→
Consider the potentiometer circuit as arranged in the figure. The potentiometer wire is 600cm long. (a) At what distance from the point A should the jockey touch the wire to get zero deflection in the galvanometer? (b) If the jockey touches the wire at a distance of 560cm from A, what will be the current in the galvanometer?

→
Figure shows a transparent hemisphere of radius 3.0cm made of a material of refractive index 2.0.
  1. A narrow beam of parallel rays is incident on the hemisphere as shown in the figure. Are the rays totally reflected at the plane surface?
  2. Find the image formed by the refraction at the first surface.
  3. Find the image formed by the reflection or by the refraction at the plane surface.
  4. Trace qualitatively the final rays as they come out of the hemisphere.

→
A spherical ball of mass m and radius r rolls without slipping on a rough concave surface of large radius R. It makes small oscillations about the lowest point, Find the time period.
→