The coefficient of induction of a choke coil is 0.1 H and resistance is 12Ω. If it is connected to an alternating current source of frequency 60 Hz, then power factor will be
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If there are n capacitors in parallel connected to V volt source, then energy stored is equal to
The length of given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be
A certain piece of silver of given mass is to be made like a wire. Which of the following combinations of length (L) and the area of cross-section (A) will lead to the smallest resistance
The magnetic flux linked with a coil is given by the equation: φ = 3t2+4t+9 Wb.The magnitude of e.m.f. induced at t = 2 s is
Minimum no. of 8 μF and 250 V capacitors, used to make a combination of 16 μF and 1000 V, is
If a ladder weighing 250 N is placed against a smooth vertical wall having coefficient of friction between it and floor is 0.3, then what is the maximum force of friction available at the point of contact between the ladder and the floor
How many times is escape velocity (ν₀)of orbital velocity (ν₀) for a satellite revolving near earth ?
At what height from the ground will the value of 'g' be the same as that in 10 km deep mine below the surface of earth
Calculate the capacitance C of the capacitor if C0 is the capacitance without dielectric
A cylindrical rod is having temperature T₁ and T₂ at its ends. The rate of heat flow is Q J-s-1. If all the linear dimensions are doubled, keeping temperature constant, then new rate of heat flow will be
In the Young's double-slit experiment, a mica slip of thickness t and refractive index μ is introduced in the ray from first source S₁. By how much distance fringes pattern will be displaced.
The root mean square velocity of the molecules of different ideal gases maintained at the same temperature is
A voltmeter of resistance 20000 Ω reads 5 volt. To make it read 20 volt, the extra resistance required is
A circular coil of radius R carries an electric current. The magentic field due the coil at a point on the axis of the coil located at a distance r from centre of the coil, such that r >> R varies
H⁺, He⁺ and O⁻⁻ all having the same kinetic energy pass through a region in which there is a uniform magentic field perpendicular to their velocity. The masses of H⁺, He⁺ and O⁻⁻ are 1 amu, 4 amu and 16 amu respectively. Then
A short magnetic needle is pivoted in a uniform magnetic field of strength 1 T. When another magnetic field of strength √3 T is applied to the needle in a perpendicular direction, then the angle through which the needle will deflect, is
Two similar bar magnets of the same mass and dimensions freely suspended by threads in a horizontal plane are found to make 12 oscillations and 15 oscillations per minute. Then their magnetic moments are in the ratio of
A dip circle is so set that its needle moves freely in the magnetic meridian. In this position, the angle of dip is 40o. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30o with the magnetic meridian. In this position, the needle will dip by an angle
If a liquid does not wet the glass, then its angle of contact is
In old age, arteries carrying blood in the human body become norrow, resulting in an increase in the blood pressure. This follows from
Two wires of same radius and length are subjected to the same load. One wire is of steel and the other is of copper. If Young's modulus of steel is twice that of copper, then ratio of elastic potential energies stored per unit volume in steel wire to that in copper wire is
The velocity of a body depends on time according to the equation ν = 20 + 0.1 t2. The body is undergoing
A weightless ladder 20 ft long rests against a frictionless wall at an angle of 60o from the horizontal. A 150 pound man is 4 ft from the top of the ladder. A horizontal force is needed to prevent it form slipping. Choose the correct magnitude from the following