## JEE Exam Questions and Answers

• What is the new size of an image of an object at infinity formed by a convex lens if a concave lens is placed between the convex lens and its image? Use the following data: Focal length...
What is the new size of an image of an object at infinity formed by a convex lens if a concave lens is placed between the convex lens and its image? Use the following data: Focal length...
The new image size would be 2.5 cm. One of the other answers already explains the math, so I’ll endeavor to explain how this happens. A concave lens curves inwards like an hourglass, while a convex lens curves outwards like an oval. Due to these differences in how the lenses are formed, the way they refract and reflect light is different. Concave separates light, but convex brings light together to a single point; it’s why ants will burn under a magnifying glass but not with glasses. Since the convex lens being placed between the object and the concave lens, it gets bigger. That’s really the simplified version of how this little experiment works. Again, since the math has already been explained, I won’t be doing that here.

• What is the size of the image? 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.
What is the size of the image? 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.
An image can be provided for a student to figure out in their geometry class the size of it. When the teacher wants the students to determine the size of an image or object, she means that the students should know the length, width, and height of the object. Linear refers to the lines of an object and can refer to the length of the image. An axis refers to the set line in a measurement for the student to use or gauge. The image in this example is a concave mirror which means that there are not straight lines. Instead, concave means that one line of the mirror curves. An equation must be set up for the formula that represents measurement.

• What is the number of common tangents to the circle x2 + y2 – 4 = 0 and x2 + y2 – 6x – 8y – 24 = 0?
What is the number of common tangents to the circle x2 + y2 – 4 = 0 and x2 + y2 – 6x – 8y – 24 = 0?
The correct answer to this question is C, 3. A tangent is a plane or straight line, which will touch a curve at a point. The point where they meet is called the end of tangency. The first references to tangents date back to 300 BC. There is also a tangent plane, which is where the flight barely touches the surface. This type of question is related to math, specifically geometry, and would mainly be on a test for this subject. It is one of the main topics of geometry, and a student of this subject would quickly know the answer.

• A man of mass 60 kg takes 35 seconds to reach the top of a building using the stairs. How much time will be taken by another man of same mass, if the powers developed by the fist man and the second...
A man of mass 60 kg takes 35 seconds to reach the top of a building using the stairs. How much time will be taken by another man of same mass, if the powers developed by the fist man and the second...
P is inversely proportional to timep1/p2=t2/t14/7=t2/35t2=4/7x35 20 sec

• What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass per unit...
What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass per unit...
2.31

• What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass...
What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass...
2.31

• What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass per unit...
What will be the percentage error in the measurement of velocity? The velocity of transverse wave in a string is given by the formula  where T is the tension in the string and m is mass per unit...
2.31

• What is the volume of a cube that has sides of length 1.7 X 10-3 m?
What is the volume of a cube that has sides of length 1.7 X 10-3 m?
4.9 X 10-9 m3Volume of a cube = a3; where ‘a’ is the side of cubeIn the question a = 1.710-3; so the volume = (1.710-3)3 = 4.91310-9but the side of the cube is given as 1.710-3 and we have to take care that the answer must be is in same format as of the side so the volume of the cube is = 4.91310-9

• What will be the dimensions of the mass, if C (velocity of light), g (acceleration due to gravity) and P (atmospheric pressure) are considered as the fundamental Quantities in MKS system?
What will be the dimensions of the mass, if C (velocity of light), g (acceleration due to gravity) and P (atmospheric pressure) are considered as the fundamental Quantities in MKS system?
C/PDimensional formula of velocity of light (C) = [LT-1]Dimensional formula of acceleration due to gravity (g) = [LT-2]Dimensional formula of atmospheric pressure (P) = [ml-1T-2],Now let M = CagbPc; [M] = [LT-1] a [LT-2] b [ml-1T-2] c,[M1] = [La+b-c] [T-a-2b-2c] [M c];a+b-c = 0; -a-2b-2c = 0; c = 1; On solving the equations we get, a = 0, b = 1, c = 1,so, M = Pg.

• The velocity of transverse wave in a string is given by the formula where T is the tension in the string and m is mass per unit length. If T=7.0 Kg, the mass of the string is 5.0 g and the length...
The velocity of transverse wave in a string is given by the formula where T is the tension in the string and m is mass per unit length. If T=7.0 Kg, the mass of the string is 5.0 g and the length...
2.31

• Which of the following statement is correct?
Which of the following statement is correct?
Kinetic Energy of a system can be changed without changing its momentumA. Inelastic collisions are the examples in which the kinetic energy of the bodies change but the momentum of the bodies remains conserved. b. Work done on a system will always increase the potential energy of the system: It will happen only in the case of conservative. In case of Non Conservative forces, the work done may dissipate in form heat, sound etc. c. In case of conservative forces the work done is equal to the change in the potential energy.

• If the ratio of specific heat of a gas at constant pressure to that at constant volume is γ, the change in internal energy of a mass of gas when the volume changes from V to 2V under constant...
If the ratio of specific heat of a gas at constant pressure to that at constant volume is γ, the change in internal energy of a mass of gas when the volume changes from V to 2V under constant...
PV I (γ-1)