List of practice Questions

A train moves from one station to another in 2 hour time. Using the speed-time graph of the motion, calculate distance covered during time interval from 0.75 hr to 1 hr.
A train standing at the outer signal of a railway station blows a whistle of frequency $400 \,Hz$ in still air. The train begins to move with a speed of $30\, m\, s^{-1}$ towards the platform. The frequency of the sound heard by an observer standing on the platform is (Speed of sound in air = $330\,m \, s^{-1})$
A train travels from one station to another at a speed of $40\, km/hour$ and returns to the first station at a speed of $60\, km/hour$. The average speed and average velocity of the train are respectively
A trait which protects from insect infestation is
A toxic substance, responsible for the chills and high fever recurring every three to four days in malarial fever, is
A town has total population $25000$, out of which $13000$ read ??he Hindustan Times and $10500$ read ??he Indian Express?
A toroidal solenoid has 3000 turns and a mean radius of 10cm. It has a soft iron core of relative permeability 2000. Find the magnetic field in the core when a current of 1.0A is passed through the solenoid.
A tower 100 m tall at a distance of 3 km is seen through a telescope having objective of focal length 140 cm and eyepiece of focal length 5 cm. Then the size of final image if it is at 25 cm from the eye
A tower subtends an angle of 30$^\circ$ at a point on the same level as the foot of the tower. At a second point h metres above the first, the depression of the foot of the tower is 60$^\circ$. The horizontal distance of the tower from the point is.
A thin uniform rod of mass m and length is hinged at the lower end to a level floor and strands vertically. It is now allowed to fall, then its upper end will strike the floor with the velocity
A thin wire of length $l$ and mass $m$ is bent in a form of semicircle. Its moment of inertia about an axis joining its free ends will be
A threatened species category includes
A tobacco plant heterozygous for a recessive character is self-pollinated and $1200$ seeds are subsequently germinated. Flow many seedlings would have the parental genotype ?
A thin uniform circular ring is rolling down an inclined plane of induction 30$^\circ$ without slipping, its linear acceleration along the inclined plane will be
A thin uniform rod ''AB'' of mass m and length L is hinged at one end A to the level floor. Initially it stands vertically and is allowed to fall freely to the floor in the vertical plane. The angular velocity the rod, when its end B strikes the floor is (g is acceleration to gravity)
A thin tube of uniform cross-section is sealed at both ends. When it lies horizontally, the middle $5\, cm$ length contains mercury and the two equal ends contain air at the same pressure $P$. When the tube is held at an angle of $60^{\circ}$ with the vertical, then the lengths of the air columns above and below the mercury column are $46\, cm$ and $44.5\, cm$ respectively. Calculate the pressure $P$ in cm of mercury. The temperature of the system is kept at $30^{\circ}C$.
A thin uniform circular disc of mass M and radius R is rotating in a horizontal plane ahout an axis passing through its centre and perpendicular to the plane with an angular velocity $\omega$ Another disc of same mass hut half the radius is gently placed over it coaxially. The angular speed o f the composite disc will be
A thin rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal haves (each having half of the original length) and one piece is made to oscillate freely in the same field. If its period of oscillation is T then $\frac{T}{T}$ is.
A thin rod of mass $m$ and length $2l$ is made to rotate about an axis passing through its centre and perpendicular to it. If its angular velocity changes from $0$ to $\omega$ in time $t$, the torque acting on it is
A thin circular ring of area A is perpendicular to uniform magnetic field of induction B. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of circuit is R. When.the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer is
A thin convex lens of focal length 10 cm and a thin concave lens of focal length 20 cm are in contact. The combination acts as:
A thin glass (refractive index $1.5$) lens has optical power of $-8\, D$ in air. Its optical power in a liquid medium with refractive index $1.6$ will be
A tensile force of $2\times10^5$ dynes doubles the length of an elastic cord whose area of cross section is 2scm Young's modulus of the material of the cord is
A teaparty is arranged for 16 people along two sides of a large table with 8 chairs on each side. Four men want to sit on one particular side and two on the other side. The number of ways in which they can be seated is
A system has internal energy equal to $E_1$, 450 J of heat is taken out of it and 600 J of work is done on it. The final energy of the system will be