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A shot is fired from a point at a distance of 200 m from the foot of a tower 100 m high so that it just passes over it horizontally. The direction of shot with horizontal is A shot is fired from a point at a distance of 200 m from the foot of a [...]

A conducting wire of length l is placed on a rough horizontal surface, where a uniform horizontal magnetic field B perpendicular to the length of the wire exists. Least values of the forces required to move the rod when a current A conducting wire of length l is placed on a rough horizontal surface where [...]

A particle is projected from ground at some angle with the horizontal. Let P be the point at maximum height H. At what height above the point P should the particle be aimed to have equal to maximum height ? A swimmer wishes to cross a 500 m river flowing at 5 km/h. His speed [...]

A long solenoid with radius 2 cm carries a current of 2 A. The solenoid is 70 cm long and is composed of 300 turns of wire. Assuming ideal solenoid model, calculate the flux linked with a circular surface if (a) it has a radius of 1cm and is perpendicular to the axis of the [...]

A hypothetical magnetic field existing in a region is given by B = B0er where er denotes the unit vector along the radial direction. A circular loop of radius a, carrying a current i, is placed with its plane parallel to A hypothetical magnetic field existing in a region is given by B = B0er [...]

A particle is moving in a circle of radius r centred at O with constant speed v. What is the change in velocity in moving from A to B(∠AOB = 40)? A particle is moving in a circle of radius r centred at O with constant speed v. What is the change in velocity in [...]

At a given place horizontal and vertical components of the earth’s magnetic field BH and BV are along X and Y-axes, respectively, as shown in the figure. What is the total flux of the earth’s magnetic field associated with an area S, if the area S is in the (i) XY-plane (ii) YZ-plane (iii) X-Z [...]

The ratio of the distance carried away by the water current, downstream, in crossing a river, by a person, making same angle with downstream and upstream is 2 : 1. The ratio of the speed of person to the water current cannot be less than by a person downstream in crossing a river making same [...]

A circular loop of radius a, carrying a current i, is placed in a two – dimensional magnetic field. The center of the loop coincides with the center of the field. The strength of the magnetic field at the periphery A circular loop of radius a carrying a current i is placed in a two [...]

A river flows with a speed more than the maximum speed with which a person can swim in still water. He intends to cross the river by the shortest possible path (i.e., he wants to reach the point on the opposite bank which directly opposite to the starting point). Which of the following is correct [...]