Test: Physics - 8

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  (V_B - V_A)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
will be

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  (ω_t   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?