a potentiometer wire of length 1 m has a resistance of 5 ω. it is connected to a 8 v battery in series with a resistance of 15 ω. determine the emf of the primary cell which gives a balance point at 60 cm.
from the figure:total resistance of the circuit, r = (rab + 15) ω = 20 ωcurrent in the circuit , \[i = \frac{v}{r} = \frac{8}{20} a\] ∴ voltage across ab, vab = i.rab = 2 vthe emf of the cell connected as above is given by: \[e = \frac{l}{l} v\_0\] here:l = 60 cm (balance point)ab = l = 1 m = 100 cm (total length of the wire) \[\therefore e = \frac{60}{100}\left( 2 \right) = 1 . 2 v\]
(a) material q with resistivity 2.63×10-8 ohm-m can be used for making electric wires because it has very low resistivity.(b) material r with resistivity 1.0 ×1015 ohm-m can be used for making handle of soldering iron because it has very high resistivity.(c) material p with resistivity 2.3 × 103 ohm-m can be used for making solar cell because it is a semiconductor. as the length of the wire increases so does the electrical resistance as electrons experience a smaller pd gradient as wire gets longer. the size of voltage per metre value decreases causing a lower drift velocity and more ions for electrons to collide with a bob of mass m is suspended by inextensible string of length l from a fixed point. the bob is given a speed of at the bottom point. find the tension in the string when string deflects through an angle 120 degree from vertical. let a and b be the two given vectorsɵ = 150° is the angle between a and bif c is the resultant vector, then: ...1also, it is given that the resultant is perpendicular to one of the given vectors. let that given vector be anow, …2putting 2 in 1, we get:now, putting c = 10, ɵ = 150° ()so, hence, smaller vector is a = 20 units trueexplanation: physical balance is very sensitive and used in labs for measuring. it is similar to beam balance. it can measure small differences in mass up to milligram. if you right click on the battery\_simple\_dynamics subsystem, you can go to mask -> look under mask. here, you will see that the state of charge is being computed in this subsystem. the ah*0.2*3600 constant block after changing to ah*0.1*3600 i then see an initial charge state of 90%. two poles of height 6 m and 11 m, respectively stand on a plane ground. if the distance between their feet is 12 m, then what is the distance between their tops? that depends on a lot of things. in particular, you would need to find the electric susceptibility of the paper. the field produced by static charge is inverse-square. the polarization of the paper varies directly with the external field, with a proportionality constant equal to the electric susceptibility. the dipole field created by the polarized paper is inverse-cube. overall, the force between the ruler and the paper will vary with the inverse fifth power of distance. to get any more detailed, you would need to know the geometry of the situation, and the charge distribution. &nbsp;an electron enters uniform electric field maintained by parallel plates and of value 'e' &nbsp; v m-1 with a velocity ' v ' ms-1.&nbsp;the plates are separated by a distance 'd' metre. what is the acceleration of the electron in the field?&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; hi trinity, let's do this one!newton's famous second law states, in math terms: f = ma applying to the first case, we have: 100 = m(4.00) => m = 100/4 = 25 kgnow apply the formula to the second case: f = 25 x 16 = 400 newtons