Let's see if you can answer these questions of IIT JEE level.

## 1.

## 2. Sunlight of intensity 1.3kWm^{-2 }is incident normally on a thin convex lens of focal length 20 cm. Ignore the energy loss of light due to the lens and assume that the lens aperture size is much smaller than its focal length. What is the average intensity of light, in kWm-2, at a distance 22 cm from the lens on the other side?

## 3. Which of the following order is/are correct for the rate of E2 reaction?

## 4. When a beam of photons of a particular energy was incident on a surface of a particular pure metal having work function (40eV), some emitted photoelectrons had had stopping potential equal to 22V, some had 12V and rest had lower values. Calculate the wavelength of incident photons assuming that at least one photoelectron is ejected with maximum possible kinetic energy.

## 5. The upper 3/4th portion of a vertical pole subtends an angle tan^{-1} 3/5 at point in the horizontal plane through its foot and at a distance 40m from the foot. What is a possible height of the vertical pole?

## 6. Two particles 1 & 2 are projected upwards from a point at the same time with velocities 5m/s and 10m/s respectively. Their angles of projection with vertical are 37 degrees and 53 degrees respectively and horizontal components of velocities are in same direction. Find the interval of time between the moments when they pass through the other common point of their trajectory.

## 7. 25mL of a 0.1M solution of a stable cation of transition metal Z reacts exactly with 25 mL of 0.04M acidified KMnO4 solution. Which of the following is most likely to represent the change in the oxidation state of Z correctly.

## 8. A circular disc rolls down an inclined plane. What is the ratio of the total kinetic energy to the rotational kinetic energy?

## 9. What is the sum of integers from 1 to 100 that are divisible by 2 or 5?

## 10. A circle touches the x-axis and also touches the circle with centre at (0,3) and radius 2. What is the locus of the centre of the circle?

## 11. Sum of infinite number of terms of G.P. is 20 and sum of their squares is 100. What is the common ratio of G.P.?

## 12. What is the minimum energy required to launch a satellite of mass m from the surface of a planet of mass M and radius R in a circular orbit at an altitude of 2R?

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