Physics Test - 7

A train of length 80 m is moving with a uniform velocity of 25 m/sec. The time taken by the train to cross a bridge 120 m long is

A cricket ball of mass 200 gms moving with a velocity of 20 m/sec is brought to rest by a player in 0.1 sec. The average force applied by the player is

Two bodies of masses m and 4m are moving with equal momentum. The ratio of their kinetic energy is

An electron moves at right angle to a magnetic field of 1.5 x 10^-2T with a speed of 6 x 10⁷m/s. If the specific charge of the electron is 1.7 x 10¹¹C/kg, the radius of the circular path will be :

The apparent depth of water in cylindrical water tank of diameter '2R' cm is reducing at the rate of 'x' cm/min when water is being drained out at a constant rate. The amount of water drained in cc per minute is _____. (n1= refractive index of air and n2= refractive index of water)

A horizontal pipe of cross-sectional diameter 5 cm carries water at a velocity of 4 m/s. The pipe is connected to a smaller pipe with a cross-sectional diameter 4 cm. What is the velocity of water through the smaller pipe?

In a stationary lift, a man is standing with a bucket full of water, having a hole at its bottom. The rate of flow of water through this hole is R0. If the lift starts to move up and down with the same acceleration such that the water flows at the rate of Ru and Rd,then

The water filled in a tank has a hole 'h' metres from the top. Find the distance 'x' where the stream of water will touch the ground from the bottom.

An incompressible fluid flows steadily through a cylindrical pipe which has radius '2R' at a point 'A' and radius 'R' at a point 'B'. If the velocity at point 'A' is 'v' along the flow of direction, what will be its velocity at point 'B'?

The cylindrical tube of a spray pump has a cross-section of 8 cm2, one end of which has 40 fine holes, each of area 10-8m2. If the liquid flows inside the tube with a speed of 0.15 m min-1, then the speed with which the liquid is ejected through the holes is

A small circular flexible loop of wire of radius r carries a current l. It is placed in a uniform magnetic field B. The tension in the loop will be doubled if :

Which of the following laws states that good absorbers of heat are good emitters?

A can is taken out from a refrigerator at 0oC. The atmospheric temperature is 25oC. If t1is the time taken to heat from 0oC to 5oC and t2is the time taken from 10oC to 15oC, then

Black body emits the radiation of maximum intensity 5000 A0, when its temperature is 12270C. If its temperature is increased by 10000C, what is the maximum intensity of emitted radiation?

A sound wave reflected at the boundary will undergo a phase change on reflection at