In photoelectric phenomenon, the number of photo electrons emitted depends on
Photoelectric current depends on the intensity of incident light,
the number of photoelectrons emitted per second is directly proportional to the intensity of incident radiation.
100 mA current gives a full scale deflection in a galvanometer of 2Ω resistance. The resistance connected with the galvanometer to convert it into a voltmeter to measure 5V is
The potential difference between the terminals of a cell in open circuit is 2.2 volts. With resistance of 5 ohm across the terminals of a cell, the terminal potential difference is 1.8 volt. The internal resistance of the cell is
A body revolved around the sun 27 times faster then the earth what is the ratio of their radii
A steel wire is 1m long and 1mm^{2} in area of crosssection. If it takes 200N to stretch this wire by 1mm, how force will be required to strech the wire of the same material and diameter from its normal length of 10m to length of 1002cm
Transformers are used in
Three capacitors of capacitances 2 μF, 4 μF and 6 μF are connected in a parallel combination. Their equivalent capacitance will be
Electric charges 1μC , − 1μC and 2 μC are placed in air at the corners A,B and C respectively of an equilateral triangle ABC having length of each side 10 cm. The resultant force on the charge at C is
A long solenoid of length L has a mean diameter D. It has n layers of winding of N turns each. If it carries a current I, the magnetic field at its centre will be
A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of 45º with the initial vertical direction is
The net charge on a current carrying conductor is
The magnetic susceptibility does not depend upon the temperature in
The force of cohesion is maximum in
A body starts from rest and has an acceleration 20 cm s⁻^{2}. What is the distance covered by the body in first 8 seconds?
Consider the following statements
Assertion (A) : On a rainy day, it is difficult to drive a car or bus at high speed
Reason (R) : The value of coefficient of friction is lowered due to wetting of the surface
Of these statements
Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. But if they are thrown vertically upwards with the same initial velocity, the ratio of the time required to reach the ground is equal to
A simple harmonic motion is represented by :y = 10 sin (20 t + 0.5). The amplitude of this motion is
A radio active nucleus with mass number 'A' splits into the nuclei whose mass numbers are in the ratio 3:2, the ratio of their radii is
A rectangular block of mass m and area of crosssection A floats in a liquid of density ρ. If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period T. Then
With respect to air, critical angle in a medium for light of red colour [λ₁] is θ. Other facts remaining same, critical angle for light of yellow colour [λ₂] will be
When a man stands a turntable stretching with two equal loads in hand and rotates. Then he folds his arm. Which of the following statement is correct
A dics of radius 1 m is rotating with an angular velocity of 10 rads⁻^{1}. The linear velocity of the dics on a point 0.5 m from its centre is
The band gap in germanium and silicon in eV respectively is
The most commonly used material for making transistor is
Heat given to a body which rises its temperature by 1�C is
The dimensions of calorie are
A 10 kg mass falls through 25 m on to the ground and bounces to a height of 0.50 m. Assume that all potential energy lost is used in heating up the mass. The temperature rise will be (Given specific heat of the material is 252 Joule/kg K)
If a,b,c are position vectors of vertices ABC, then the position vector of a centroid of ∆ABC is
In a biprism expt., by using light of wavelength 5000 Å, 5 mm wide fringes are obtained on a screen 1.0 m away from coherent sources. The separation between two coherent sources is
A child is sitting on a swing. Its minimum and maximum heights from the ground are 0.75 m and 2m respectively, its maximum speed will be
Dispersion is explained on the basis of
Consider a uniform electric field of magnitude . The net flux of this uniform electric field through a cube of side 40 cm, oriented so that its faces are parallel to the coordinates, has magnitude
When convex lens made of a material having refractive index 1.21 focal length 25cm is immersed in water, then lens behave like a
An insect crawls up to hemispherical surface very slowly (see the figure ). The coefficient of friction between the insect and the surface is 1/3. If the line joining the centre of the hemispherical surface to the insect makes an angles α with the vertical ,the maximum possible value of α is given by
Consider a rubber ball freely falling from a height h = 4.9 m onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then the velocity as a function of time and the height as a function of time will be 
An object is weighed at the equator by a beam balance and spring balance, giving readings W_{b} and W_{s} respectively. It is again weighed in the same manner at the north pole, giving readings of W b ′ and W s ′ respectively. Assume that the acceleration due to gravity is the same everywhere and that the balances are quite sensitive.
A parallelplate capacitor fixed with a dielectric slab is connected to a battery. After the capacitor is fully charged, the dielectric is removed without disturbing the remaining circuit. Then
A short linear object of length b lies along the axis of a concave mirror of focal length f at a distance u from the pole of the mirror. The size of the image is approximately equal to
The distances covered by a freely falling body in its first, second, third, ......, n^{th} seconds of its motion
Which of the following statements are correct?







