Mix Test - 3...

Six resistors, each of resistance R, are connected as shown in the figure. What is the effective resistance between points A and B?

A ball, which is at rest, is dropped from a height of 'h' metres. As it bounces off the floor, its speed is 80% of what it was just before touching the ground. The ball will rise to a height of

If the radius of Earth shrinks by 1.5% (mass remaining the same), then the value of acceleration due to gravity would change by

Wires AB and BC, each of length L/2, are made of the same material. The radius of wire AB is 2r and that of wire BC is r. The current I flows through the composite wire. Which of the following statements is true?

In a semiconductor, it is found that th of the total current is carried by electrons and the remaining by holes. If at this temperature, the drift speed of electrons is 2.5 times that of the holes, then the ratio of the number density of electrons to that of holes is

Two wires A and B of the same material having radii in the ratio 1 : 2 carry currents in the ratio 4 : 1. The ratio of the drift speeds of electrons in A and B is

What is the dimensional formula of Planck's constant?

A convex lens of focal length 50 cm and a concave lens of focal length 100 cm are separated by a distance of 10 cm. What is the power of combination?

The primary of a transformer has 400 turns, while the secondary has 2000 turns. If the power output from the secondary at 1000 V is 12 kW, then the resistance of the primary is 0.2, the resistance of the secondary is 2 and the efficiency of the transformer is 80%. The power loss in the primary is

In a double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. What will happen in the interference pattern?

A 0.5 kg mass moving with a speed of 1.5 m/s on a horizontal smooth surface collides with a nearly weightless spring of force constant k = 50 N/m. The maximum compression of the spring would be

A Carnot engine operates with a source at 500 K and a sink at 375 K. The engine consumes 600 kcal of heat per cycle. The heat rejected to the sink per cycle is

The threshold wavelength for a metal whose work function is W₀ is . What is the threshold wavelength for a metal whose work function is W₀/2?

A solid cylinder of mass M and radius R rolls down an inclined plane without slipping. In doing so, it comes down a height h. The speed of its centre of mass when it reaches the bottom is

The force of attraction between the plates of an air-filled parallel plate capacitor having charge Q and area of each plate A is given by