Two charges of magnitude Q and two charges of magnitude –q are placed at the opposite corners of a square of side length ‘a’. If the resultant force on a charge Q is zero than
Workdone in carrying a charge ‘Q’ from ‘A’ to ‘B’ (as shwon in figure) on a circle of radius ‘r’ with a charge ‘Q’ at the centre is
If the surface density of charge be σ electric field near the surface would be
A charged particle of mass 0.1 g is in equilibrium in an electric field E = 98 N/C. The charge on the particle is
An electric charge ‘q’ is lying at the open end of a cylindrical vessel. The flux coming out of the cylinder will be
The inward and outward electric flux for a closed surface in units of
N - m2/coulomb are respectively 8x103 and 4x103 Then the total charge inside the surface is
A bullet of mass 2g is having a charge of 2 μC.Through what potential difference must be accelerated, starting from rest, to acquire speed of 10 m/s?
On moving a charge of 20 coloumbs by 2cm, 2J of work is done, then the potential difference between the points is
The capacitance of a parallel plate condenser does not dpened upon
A semi-circular are of radius ‘a’ is charged uniformly and the charge per unit length is λ The electric field at its centre is
A condenser ‘A’ has a capacity of 15 μF when it is filled with a medium of dielectric constant 15. Another condenser has a capacity of 1 μF with air between the plates. Both are charged separately by a battery of 100V. After charging both are connected in parallel without the battery and dielectric material being removed. The common potential now is
The unit of permittivity of free space ∈0 is
Seven resistance are connected as shown in the figure. The equivalent resistance between A and B
Two charge of magnitude q1 = 2x10-7 C and q2 = 3x10-7 C are placed 10 cm apart. The electric field produced by q2 on q1 is
Six resistors each of value 10 Ω are connected to a 5 volt battery as shown in the figure. The reading of ammeter ‘A’ is
The potential difference between points ‘A’ and‘B (VB - VA)in the figure if R = 0.7 Ω is
If a wire of resistivity ρ is streched to double its length, then its new resitivity will
The internal resistance of a primary cell is 4Ω It generates a current of 0.2 A in an external resistance of 21 ΩThe rate at which chemical energy is consumed in providing the current is
The relation between Faraday constant F, electron charge e, and Avogadro Number N is
In the circuit, as shown in Fig. The heat produced by 6 Ω resistance due to current flowing in it is 60 calories per second. The heat generated across 3-ohm resistance per second will be
A 100W bulb B1 and two 60W bulb B2 and B3 are connected to a 250 V source as shown in the Fig. Now W1, W2 and W3 are the output powers of the bulbs B1 , B2 and B3 respectively ,Then
A solenoid 30 cm long is made by winding 2000 loops of wire on an iron rod whose cross section is 1.5 cm2 If the relative permeability of the iron is 600, what is the self inductance of the solenoid
A magnetic needle lying parallel to a magnetic field requires W units of work to turn it through The torque needed to maintain the needle in this position
A charged particle of mass 10-3 kg and charge + 10-5coulomb enters a magnetic field of induction one tesla. If g = 10m/s2for what value of velocity it will pass straight through it without deflection?
A bar magnet of magnetic moment μ is bent to form a semi-circle. Its magnetic moment will become
At a given place on the earth’s surface the horizontal component of magnetic field is 3.2 x 10-5 tesla and the resultant magnetic field is 6.4 x 10-5 tesla. The angle of dip at that place is:
A short magnetic needle is pivoted in a uniform magnetic field of strength 1T. When another magnetic field of strength √3 T is applied to the needle in a perpendicular direction, the needle deflects through an angle θ where θ is
An electron moving in a circular orbit of radius R with a period T is equivalent to a magnetic dipole of dipole moment
Current is flowing in a one turn circular coil. If the coil is bent into a two turn coil of smaller radius, then the magnetic field at the centre of the coil will become
A copper rod moves parallel to the horizontal direction.The induced emf developed across its ends due to earths magnetic field will be maximum at the
The figure below shows a resistor and a capacitor connected in series with a 25 V rms alternation supply
What is the r.m.s. potential difference between P and Y given that the r.m.s. potential difference between X and
P is 15 V?
The equation of an alternating voltage is E = 220 sin (ωt a π/6 )nd the equation of the current in the circuit is I = 10 sin (ωt - π/6)What is the impedance of the circuit?
In the circuit shown in Fig. the r.m.s currents I1, I2 and I3, are altered by a varying the frequency ƒ of the oscillator. The output voltage of the oscillator remains sinusoidal and has fixed amplitude.Which curves in Fig.
indicate correctly the variations with frequency of the current I1, I2 and I3?