BITSAT Physics Test - 6

Three copper wires have lengths and cross-sectional areas of (l and A), (2l and A/2) and (l/2 and 2A). Resistance will be minimum in

When a resistance of 2 Ω is connected across the terminals of a cell, the current is 0.5 amperes. When the resistance is increased to 5 ohm, the current is 0.25 amperes. The internal resistance of the cell is

An electron of charge 'E' is liberated from a hot filament and attracted by an anode of potential 'V' volts positive with respect to the filament. The speed of the electron of mass m when it strikes the anode is

The de Broglie wavelength λ associated with an electron having kinetic energy E is given by the expression

In a car spark coil, an e.m.f. of 40000 V is induced in a secondary when the primary current changes from 4 A to zero in 10μs. Find the mutual inductance between the primary and secondary windings of the spark coil

A parallel plate capacitor is first charged and then a dielectric slab is introduced between the plates. The quantity that remains unchanged is

An electric dipole placed in a non-uniform electric field experiences

A 60 kg weight is dragged on a horizontal surface by a rope to 2 metres. If coefficient of friction is μ=0.5, the angle of rope with the surface is 60^o and g=9.8 m/sec², then work done is

If distance between earth and sun become four times, then time period becomes

In which of the following process, convection does not take place primarily?

The equation of state for 5 g of oxygen at a pressure P and temperature T, when occupying a volume V, will be (where R is the constant)

A potential difference of 2V exists across a potentiometer wire of 2m length. When the potential difference across a 2Ω resistance of a second circuit is measured by this potentiometer wire, it amounts to 5mm balancing length. The current in the second circuit is

The effective length of a magnet is 31.4 cm, and its pole strength is 0.5 A-m. If it is bent in the form of a semicircle,then its new magnetic moment will be

When the free surface area of a liquid is increased, the surface tension of the liquid

If an air-bubble of radius 0.4 mm at a depth h in water having surface tension of 72*10^⁻3 N-m^⁻1 and density 1000 kg-m^⁻3 is in equilibrium then, the value of h is (Take g=10 m-s^⁻2)

For a constant hydraulic stress on an object, the fractional change in the object's volume (Δ V/V) and its bulk modulus (K) are related as

A car is driven for 0.8 s. If the car travelling initially with 36 km − h^⁻1 is stopped by the driver after observing a signal by deceleration of 5 m − s⁻², then total distance travelled by the car before coming to rest, is

A cricketer hits a ball with a velocity 25 m/s at 60^o above the horizontal. How far above the ground it passes over a fielder 50 m from the bat (assume the ball is struck very close to the ground)

The maximum speed of a car on a road-turn of radius 30 m, if the coefficient of friction between the tyres and the road is 0.4, will be

A person of 70kg mass is lifted by a helicopter with the help of rope hanging from it. If the helicopter is rising with an acceleration of 4 ms^-2, the tension in the rope is (g=10 ms^-2)

The ability of eye to focus near as well as distant objects is called

When the potential energy of a particle executing simple harmonic motion is one-fourth of the maximum value during the oscillation, its displacement from the equilibrium position in terms of its amplitude a is

Which of the following function represents a simple harmonic motion?

A ray of light is incident at 60^o on a prism of refracting angle 30^o . The emergent ray is at an angle 30^o with the incident ray. The value of refractive index of the prism is

A person standing on a rotating platform has his hands lowered. He suddenly outstreches his arms. His angular momentum

A wheel is rotating at 900 r.p.m. about its axis When power is cut off it comes to rest in 1 minute The angular retardation in rad/s² is

Two rings of the same radius and mass are placed such that their centres are at a common point and their planes are perpendicular to each other. The moment of inertia of the system about an axis passing through the centre and perpendicular to the plane of one of the ring is (mass = and radius = r)

The relation between Faraday constant (F), chemical equivalent (E) and electrochemical equivalent (Z) is

The densities of two substances are in the ratio 5:6 and their specific heats are in the ratio 3:5 respectively. Then their thermal capacities per unit volume will be in the ratio

At N.T.P. one mole of diatomic gas is compressed adiabatically to half of its volume (γ = 1.41). The work done on gas will be

Young's modulus of a material has the same units as

For diffraction of light, the condition for nth secondary minimum is that path difference is equal to [Here a is the width of slit, n is the order of diffraction, λ is the wavelength of light and θ n gives the direction of nth secondary minimum ]

The displacement of the interfering light waves are y₁ = 4 sin ωt and y₂ = 3 sin (ωt + π/2). What is the amplitude of the resultant wave

Two waves of intensities I and 4 I superimpose, then maximum and minimum intensities are

For production of beats, the two sources must have

A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency the work done by the motor in one rotation will be

The average resisting force that must act on a 5 Kg mass to reduce its speed from 65cms^-1 to 15cms^-1 in 0.2s is