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The armature of dc motor has `20Omega` resistance. It draws current of 1.5 A when run by 220 V dc suppy. The value of back induced in it will

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As shown in figure after a long time the battery is disconnected and short circuiting the points A & B. The current in circuit after 2ms after the short circuit

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In ac circuit with voltage V and current I, the power dissipaled

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In the transmission of a.c. power through transmission lines, when the voltage is shapped up n times, the power loss in

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The impedance of a circuit consists of `3Omega`resistance and `4Omega` reactance. The power factor of the circuit

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An LC circuit contains a 20 mH inductor and a `50muF` capacitor with an initial charge of 10 mc. The resistance of the circuit is negligible. At the instant the circuit is closed be t = 0. At what time is the energy stored compeletly

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An LC circuit contains a 20mH inductor and a `50muF` capacitor with an initial charge of 10mC. The resistance of the circuit is negligible. Let the instant the circuit is closed to be `t = 0.`At what times is the total energy shared equally between inductor and the

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Two moving coil meters, M1 and M2 have the following particulars: R1 = 10 Ω, N1 = 30, A1 = 3.6 × 10–3 m2 , B1 = 0.25 T R2 = 14 Ω, N2 = 42, A2 = 1.8 × 10–3 m2 , B2 = 0.50 T (The spring constants are identical for the two meters). Determine the ratio of(i) current sensitivity (ii) voltage sensitivity of M2 and M1

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In a chamber, a uniform magnetic field of 6.5 G (1 G = 10 –4 T) is maintained. An electron is shot into the field with a speed of 4.8 × 106 m s–1 normal to the field. Explain why the path of the electron is a circle. Determine the radius of the circular orbit. (e = 1.5 × 10–19 C, `m_e` = 9.1×10–31

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A magnetic needle free to rotate in a vertical plane parallel to the magnetic meridian has its north tip pointing down at 22° with the horizontal. The horizontal component of the earth’s magnetic field at the place is known to be 0.35 G. Determine the magnitude of the earth’s magnetic field at the

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A short bar magnet has a magnetic moment of 0.48 J T –1. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on the

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A permanent magnet in the shape of a thin cylinder of length 10 cm has M = 106 A/m. Calculate the magnetisation current

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A current carrying circular loop of radius R is placed in the x-y plane with centre at the origin. Half of the loop with x > 0 is now bent so that it now lies in the y-z

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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

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When a certain length of wire is turned into one circular Loop, the magnetic induction at the centre of coil due to some current flowing is B0 . If the same wire is turned into three Loops to make a circular coil, the magnetic induction at the centre of this coil for

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A straight wire of length 30 cm and mass 60 milligrawm lies in a direction `30^0` east of north. The earth's magnetic field at this site is horizontal and has a magnitude of 0.8 G. What current must be passed through the wire so that it may float in air ?

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A Galvanometer has a resistance G and 9 current `I_G` flowing in it produces full scale deflection. S1 is the value of the shunt which converts it into an ammeter of range 0 to I and S2 is the value of the shunt for the range 0 to 2I. The ratio `S_1/ S_2` is

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In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an ele. potential V and then made to describe semicircular paths of radius R using a magnetic field B.If V and B are kept constant, the ratio Charge on the ion /mass of the ion will be proportional

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The effective length of a magnet is 31.4 cm and its pole strength is 0.5 A.m. The magnetic moment, if it is bent in the form of a semicircle will be ......................Amp.`m^2`

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Electric flux emanating through a surface element `dS = 5hati` placed in an electric field `E=4hati + 4hatj + 4hatk`

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