List of top Physics Questions asked in COMEDK UGET

Time period of oscillation of a mass suspended from a spring is \( T \). If the spring is cut into four equal parts and the same mass is suspended from one of the parts, the fractional change in time period is

Ten cells, each having internal resistance \( 1\Omega \) and emf \( 1.5 \, V \) are connected in series. But unknowingly 3 cells are connected wrongly in series. The effective internal resistance and emf of the series combination are respectively:

Rods \( A \) and \( B \) have their lengths in the ratio \( 1 : 2 \). Their thermal conductivities are \( K_1 \) and \( K_2 \) respectively. The temperatures at the ends of each rod are \( T_1 \) and \( T_2 \). If the rate of flow of heat through the rods is equal, the ratio of area of cross section of \( A \) to that of \( B \) is

The heat required to increase the temperature of 4 moles of a mono-atomic ideal gas from \( 273^\circ C \) to \( 473^\circ C \) at constant volume is

Which physical quantity has the unit joule tesla?

Fusion reaction is more energetic than fission reaction because

The ratio of the number of turns of the primary coil to the secondary coil of an ideal transformer is \( 5 : 1 \). The primary is connected to \( 220 \, V \) supply. What is the output power of the transformer if the output resistance is \( 11 \Omega \)?

In to a uniform transverse magnetic field, two charged particles having the same mass and charge enter and move in two different circular paths. The ratio of the radii of curvatures of the circular paths is \( 1 : 4 \). What would be the ratio of their respective velocities?

The wire made of Phosphor bronze is used as the suspension strip in the moving coil galvanometer, because:

To get 300 MW electric power for half an hour, how much mass is to be completely converted into energy?

What is the dimensional formula for electric flux?

The electric field versus distance graph is shown as given. Select the correct statement from the following.
E – electric field, R – radius, r – distance from the centre

One end of a nylon rope of length \( 1 \) and diameter \( 10 \, \text{mm} \) is fixed to free limb. A monkey weighing \( 100 \, \text{N} \) jumps to catch the free end and stays there. The change in diameter of the rope is (Young's modulus of the wire is \( Y \) and Poisson Ratio is \( \sigma \))

Two spherical planets \( P \) and \( Q \) have the same uniform density \( \rho \), and masses \( M_P \) and \( M_Q \), and surface areas \( A \) and \( 4A \) respectively. Another spherical planet \( R \) also has the same uniform density \( \rho \), and its mass is \( M_P + M_Q \). The escape velocities from these planets is

The value of universal gravitational constant was first determined by

A wind mill converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. The electrical power output \( P \) is related to the velocity of wind \( v \) as

A current of 2 A is passed through the primary coil. The total flux linked with the secondary coil, which is closely wound over the primary is \( 2000 \times 10^{-6} \, \text{weber} \). What is the induced emf in the secondary if the current through the primary increases at a rate of \( 0.2 \, \text{A s}^{-1} \)?

A bullet of momentum \( p \) is fired into a door and gets embedded exactly at the center of the door. The door is \( 1.0 \, \text{m} \) wide and weighs \( 12 \, \text{kg} \). It is hinged at one end and rotates about a vertical axis practically without friction. The angular speed of the door just after the bullet embeds into it is:

Water from a tap emerges vertically downwards with an initial speed of \( 1.0 \, \text{ms}^{-1} \). The cross-sectional area of the tap is \( 1 \, \text{cm}^2 \). Assume that the pressure is constant throughout the stream of water and that the flow is steady. The cross-sectional area of the stream \( 15 \, \text{cm} \) below the tap is \( (g = 10 \, \text{ms}^{-2}) \)

Three point charges \( -1C, +1C, +1C \) are placed at points \( A, B, C \) respectively of a triangle \( ABC \). What is the total potential energy of the system? [given \( AB = AC = 6 \, \text{cm} \) and \( BC = 3 \, \text{cm} \)]

A beam of light parallel to the principal axis of a concave and convex lens, first passes through the concave lens of focal length \( 0.5 \, \text{m} \) and then through the convex lens of focal length \( 1.75 \, \text{m} \). If the lenses are placed \( 1.25 \, \text{m} \) apart, which of the given statement is true?

When a body of refractive index \( \mu = 1.4 \) is put into a liquid, the body becomes invisible. What would be the refractive index of the medium?

Three ideal diodes and resistors connected to the cell of negligible internal resistance is as shown. Find the current passing through the \( 10\Omega \) resistor.

A particle 'X' carrying a charge \( +Q \) is moving in a circular path of radius \( R \) around another particle 'Y' having a charge \( -Q \) with a frequency \( \nu \). Then the mass \( m \) of the charged particle is:

A car, starting from rest, accelerates at the rate \( f \) through a distance \( S \), then continues at constant speed for some time \( t \) and then decelerates at the rate \( \frac{f}{2} \) to come to rest. If the total distance is \( 5S \), then