Physics Mock Test-10

The unit of surface tension is

Which two of the following five physical parameters have the same dimensions?
1. energy density
2. refractive index
3. dielectric constant
4. Young’s modulus
5. magnetic field

A condenser of 250 μF is connected in parallel to a coil of inductance of 0.16 mH, while its effective resistance is 20Ω. Determine the resonant frequency.

A series L-C-R circuit contains inductance 5 mH, capacitance 2 μF and resistance 10Ω. If a frequency AC source is varied, then what is the frequency at which maximum power is dissipated?

As per Bohr model, the minimum energy (in eV) required to remove an electron from the ground state of doubly ionised Li-atom (Z=3) is

A carbon film resistor has colour code green, black, violet, gold. The value of the resistor is

A galvanometer of 50 Ω resistance has 25 divisions. A current of 4×10⁻⁴ A gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volt, it should be connected with a resistance of

A photosensitive metallic surface has work function, hν₀. If photons of energy 2hν₀ fall on this surface, the electrons come out with a maximum velocity of 4×10⁶m/s. When the photon energy is increased to 5hν₀, then maximum velocity of photoelectrons will be

CO₂ laser uses

A conductor of length 5 cm is moved parallel to itself with a speed of 2 m/s, perpendicular to a uniform magnetic field of 10⁻³ Wb/m². The induced emf generated is

A resistor 30Ω, inductor of reactance 10 Ω and capacitor of reactance 10 Ω are connected in series to an a.c. voltage source. The current in the circuit is

In electromagnetic wave, according to Maxwell, changing electric field gives

B is doped in Si or Ge, then we will get

A Si and a Ge diode has identical physical dimensions. The bandgap in Si is larger than that in Ge. An identical reverse bias is applied across the diodes

A hollow sphere of radius 0.1m has a charge of 5×10⁻⁸C. The potential at a distance of 5cm from the centre of the sphere is
(1/4πε₀=9×10⁹NM²C⁻²)

Radius of orbit of satellite of earth is R. Its kinetic energy is proportional to

At what height h above earth, the value of g becomes g/2 (where R=radius of earth)?

A 2 kg mass starts from rest on an inclined smooth surface with inclination 30° and length 2 m. How much will it travel before coming to rest on a frictional surface with frictional coefficient of 0.25?

A vertical spring with force constant k is fixed on a table. A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d. The net work done in the process is

A bar magnet with magnetic moment 2.5×10³ JT⁻¹ is rotating in horizontal plane in the space containing magnetic induction B=4×10⁻⁵ T. The work done in rotating the magnet slowly from a direction parallel to the field to a direction 45⁰ from the field, is (in joule)

A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coils of n turns will be

A long straight wire of radius a carries a steady current I. The current is uniformly distributed over its cross-section. The ratio of the magnetic field B and B’ at radial distances a/2 and 2a respectively, from the axis of the wire is

A cricketer can throw a ball to a maximum horizontal distance of 100 m. With the same effort, he throws the ball vertically upwards. The maximum height attained by the ball is

A particle is moving in a circle with uniform speed v. In moving from a point to another diametrically opposite point

A car moves from X to Y with a uniform speed v(u) and returns to Y with a uniform speed v(d). The average speed for this round trip is

Two cars A and B moving with same speed of 45 km/hr along same direction. If a third car C coming from the opposite direction with a speed of 36 km/hr meets two cars in an interval of 5 minutes, the distance of seperation of two cars A and B should be (in km)

From a disc of radius R, a concentric circular portion of radius r is cut-out so as to leave an annular disc of mass M. The moment of inertial of this annular disc about the axis perpendicular to its plane and passing through its centre of gravity is

Moment of inertia of a uniform circular disc about a diameter is I. Its moment of inertia about an axis perendicular to its plane and passing throught a point on its rim will be

One-fourth length of a spring of force constant K is cut away. The force constant of the remaining spring will be

The displacement of an object attached to a spring and executing simple harmonic motion is given by x=2×10⁻² cos πt metre. The time at which the maximum speed first occurs is

A black body is at 727⁰C. It emits energy at a rate which is proportional to

Perfectly black body radiates the energy 18 J/s at 300K. Another ordinary body of e=0.8 having same are at 500K will radiate

Eight drops of a liquid of density ρ and each of radius a are falling through air with a constant velocity 3.75 cms⁻¹. When the eight drops coalesce to from a single drop the terminal velocity of the new drop will be

Given a sample of radium-226 having half-life of 4 days. Find the probability, a nucleus disintegrates after 2 half-lives.

A radioactive element forms its own isotope after 3 consecutive disintegrations. The particle emiited are

An object is placed 30 cm away from a convex lens of focal length 10 cm and a sharp image is formed on a screen. Now, a concave lens is placed in contact with the convex lens. The screen now has to be moved by 45 cm to get a sharp image again. The magnitude of focal length of the concave lens is (in cm)

A thin equiconvex lens of refractive index 3/2 and radius of curvature 30 cm is put in water (refractive index = 4/3) , its focal length is

The dimensions of latent heat are

An experiment takes 10 minutes to raise temperature of water from 0⁰C to 100⁰C and another 55 minutes to convert it totally into stream by a stabilized heater. The latent heat of vapourization comes out to be

In Young’s double slit experiment, the locus of the point P lying in a plane with a constant path difference between two interfering waves is

In Young’s double slit experiment, the fringe width is 1×10⁻⁴ m, if the distance between the slit and screen is doubled and the distance between two slits is reduced to half and the wavelength is changed from 6.4×10⁻⁷ m to 4.0×10⁻⁷ m, then the value of new fringe width will be

In the experiment for determination of velocity of sound in air, using the resonance column method, the length of the air column that resonates in the fundamental mode with a tuning fork is 0.1 m. When this length is changed to 0.35 m, the same tuning fork resonates with the 1st overtone. Calculate the end correction

When sound is produced in an aeroplane with a velocity of 200 m/s horizontally, its echo is heard after 10√5 seconds. If velocity of sound in air is 300 ms⁻¹ the elevation of aircraft is

When a mass M is attached to the spring of force constant k, then the spring stretches by l. If the mass oscillates with amplitude l, what will be the maximum potential energy stored in the spring?

A spring gun of spring constant 90 N/cm is compressed 12 cm by a ball of mass 16g. If the trigger is pulled,the velocity of the ball is