Electrons ejected from the surface of a metal, when light of certain frequency is incident on it, are stopped fully by a retarding potential of 3 volts Photo electric effect in this metallic surface begins at a frequency 6 x 1014s ^-1 The frequency of the incident light in s^-1 is [h=6 x 10^-34J-sec;charge on the electron=1.6x10^-19C]

Trajectories of two projectiles are shown in figure. Let and be the time periods and and their speeds of projection. Then

A body is projected up a smooth inclined plane with a velocity from the point as shown in figure. The angle of inclination is and top of the plane is connected to a well of diameter 40 m. If the body just manages to cross the well, what is the value of ? Length of the inclined plane is , and

The equation of the circumcircle of the triangle formed by the lines  and y=0 is

Which of the substance or has the highest specific heat? The temperature time graph is shown

The figure shows a system of two concentric spheres of radii and and kept at temperatures and respectively. The radial rate of flow of heat in a substance between the two concentric spheres, is proportional to

If the line y = x + 3 meets the circle  at A and B, then equation of the circle on AB as diameter is

An electric lamp is fixed at the ceiling of a circular tunnel as shown is figure. What is the ratio the intensities of light at base A and a point B on the wall

The distance between a point source of light and a screen which is 60 cm is increased to 180 cm. The intensity on the screen as compared with the original intensity will be

The pole of the straight line 9x + y – 28 = 0 with respect to the circle  is

Pole and polar are one of the important parts of the circle, many questions can be based on these parts. It should be remembered that while writing the equation of polar for a pole, the coefficients of square terms in the equation of the circle is one. If the equation of the circle does not have coefficients as one, then make it one before solving the question.

Three rods of equal length are joined to form an equilateral triangle O is the mid point of Distance remains same for small change in temperature. Coefficient of linear expansion for and is same, but that for is Then

A point source causes photoelectric effect from a small metal plate Which of the following curves may represent the saturation photocurrent as a function of the distance between the source and the metal?

One of the following figures respesents the variation of particle momentum with associated de Broglie wavelength
a)
b)
c)

Two circular discs A and B with equal radii are blackened. They are heated to some temperature and are cooled under identical conditions. What inference do you draw from their cooling curves?

Which of the curves in figure represents the relation between Celsius and Fahrenheit temperatures

The area of circle centred at (1, 2) and passing through (4, 6) is

The area of a circle is the space occupied by the circle in a two-dimensional plane. Area of circle = πr² (π = 22/7).