The average power dissipation in a pure capacitance in A.C. circuit is
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A 500 kg car takes a round turn of radius 50 m with a velocity of 36 km/hr. The centripetal force is
A bomb of mass 3.0 kg explodes in air into two pieces of masses 2.0 kg and 1.0 kg. The smaller mass goes at a speed of 80 m/s. The total energy imparted to the two fragments is
Two resistances of 400 Ω and 800 Ω are connected in series with 6 volt battery of negligible internal resistance. A voltmeter of resistance 10,000 Ω is used to measure the potential difference across 400 Ω . The error in the measurement of potential difference in volts approximately is
The work functions for sodium and copper are 2 eV and 4 eV. Which of them is suitable for a photocell with 4000Å light
300 Joule of work is done in sliding a 2 kg. block on an inclined plane to a height of 10 meters. Taking value of acceleration due to gravity 'g' to be 10 m/s2, work done against friction is
A Zener diode has a breakdown voltage of 9.1 V with a maximum power dissipation of 364 m W. What is the maximum current that the diode can withstand?
The electrostatic capacity of a capacitor depends upon its
The ratio of the lengths of two wires A and B of same material is 1:2 and the ratio of their diameter is 2:1. They are stretched by the same force, then the ratio of increase in length will be
The escape velocity of a body on the surface of the earth is 11.2 km/s. If the earth's mass increases to twice its present value and the radius of the earth becomes half, the escape velocity would become
If the temperature of a hot body is increased by 50% then the increase in the quantity of emitted heat radiation will be
A rope of mass 0.1 kg is connected at the same height of two opposite walls. It is allowed to hang under its own weight. At the contact point between the rope and the wall, the rope makes an angle θ = 10o with respect to horizontal. The tension in the rope at its midpoint between the walls is
Which of the following is NOT an illustration of Newton's third law ?
On connecting a battery to the two corners of a diagonal of a square conductor frame of side 'a', the magnitude of magnetic field at the centre will be
Two spheres of equal masses but radii r1 and r2 are allowed to fall in a liquid of infinite column. The ratio of their terminal velocities are
A stone is dropped from rest from the top of a tower 19.6 m high. The distance travelled during the last second of its fall is (given g = 9.8 m/s2)
The susceptibility of magnetic substance for different purposes is determined by its
A force of 100 dynes acts on mass of 5 gm for 10 sec. The velocity produced is
A block is suspended from a spring and makes SHM. When the displacement is equal to half the amplitude, the ratio of the kinetic to potential energy is
If the horizontal range of a projectile is equal to the maximum height reached, then the corresponding angle of projection is
A trough contains mercury to a depth of 3.6 cm. If the same amount of mercury is poured in it then the height of mercury in the trough will be
Fraunhofer's lines, commonly visible in the sun's spectrum, are the examples of
A circular disc is to be made by using iron aluminium, so that it acquires maximum moment of inertia about its geometrical axis. It can be obtained with
The dimensional formula for universal gravitational constant is
The liquid meniscus in a capillary tube will be convex, if the angle of contact is
A bulb has specification of one kilowatt and 250 volts, the resistance of bulb is
A steel bridge in a town is 200m long. The minimum temperature in winter in the town is 10 oC and maximum in summer is 40 oC. The change in length of the bridge from winter to summer is ( α for steel is 11 x 10 − 6 ∕ oC )