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Two copper wires, one of length 1 m and the other of length 9 m, are found to have the same resistance. Their diameters are in the ratio :

An electrical conductor's electrical resistance is the resistance to the passage of an electric current through it. The resistance of a wire... View Article

Explain parallax method for measuring distance of a nearly star.

The process of measuring two angles and sides of a triangle created by the star, earth on one side, and the other side six months later is known... View Article

A parallel plate capacitor is charged and then isolated. The effect of increasing the plate separation on charge, potential and capacitance respectively are:

The capacitor is charged and then isolated, according to the question. It indicates that as plate separation increases or decreases, the charge... View Article

If momentum of an object is increased by 10% then its kinetic energy will increase by?

Answer: 21% The relationship between the kinetic energy and momentum of a body is K.E=P2/2m. Given that, if momentum is increased by 10%, then... View Article

The minimum distance between an object and its real image formed by a convex lens is:

Suppose I be the real image of an object at O. Let d represent the distance between them. If the image is x distance from the lens's centre, then... View Article

A Zener diode works on: A) zero bias B) reverse bias C) forward bias D) infinite bias

Answer: (b) reverse bias When a PN junction diode is heavily doped with impurities, the depletion layer's breadth narrows due to the larger... View Article

A particle of mass M at rest decays into two masses m1 and m2with non-zero velocities. What is the ratio λ1/λ2 of de Broglie wavelengths of particles?

We know that, according to de-Broglie’s hypothesis, the momentum of the particle is, p = hc/λ Here, h is Planck’s constant... View Article

The gravitational force between two bodies is ′ F ′ . If the mass of each body is doubled and distance between them is halved then the force between them will be :

The force between two masses is directly proportional to the product of their masses and inversely proportional to the square of the distance... View Article

Assertion In a simple battery circuit, the point of the lowest potential is positive terminal of the battery. Reason The current flows towards the point of the higher potential, as it does in such a circuit from the negative to the positive terminal. In a simple battery circuit, the point of the lowest potential is positive terminal of the battery.

Answer: A battery's positive terminal is the place of highest potential, and current flows from there to the negative terminal, or from +ve to... View Article

How many images of an object are formed if two adjacent walls and the ceiling of a rectangular room are mirror surfaced?

The incident ray will be reflected at an angle in a plane mirror. The incidence angle and the reflection angle will be the same. When two mirrors... View Article

Which of the following has more inertia? A five-rupee coin or a one-rupee coin.

Inertia is a property of a body that causes it to prefer to be at rest or in motion. Let us now investigate the factor that causes inertia. As a... View Article

The frequency n of vibration of stretched string depends upon its length l, its mass per unit length m and Tension t in the string Obtain dimensionally an expression for frequency n.

Let the relation be: Frequency v = KLafbmc where k is a dimensionless constant The dimension of each quantity are: L=[M0L1To] f=[M1L1T−2]... View Article

Two forces, while acting on a particle in opposite; directions, have the resultant of 10N. If they act at right angles to each other, the resultant is found to be 50N. Find the two forces.

The resultant force is described as the total amount of force acting on the object or body along with the direction of the body. The resultant... View Article

What will happen to a compass needle when the compass is placed below a wire and a current is made to flow through the wire? Give a reason to justify your answer.

Assume we're holding a current-carrying straight conductor in our right hand, with the thumb pointing in the current's direction. The right-hand... View Article

An object is thrown vertically upwards to a height of 10 m. Calculate its (a) Velocity with which it was thrown upward. (b) Time taken by the object to reach the highest point.

We have given the maximum vertical height attained by the object is h=10m . (a)To calculate the initial velocity of the object with which it is... View Article

A circular loop of radius 0.0157 m carries a current of 2.0 amp.The magnetic field at the center of the loop is

The magnetic field due to a circular loop is given by: B = μ0/4π 2πi/r =10−7 × 2π×2/ 0.0157 = 8 ×... View Article

A compass needle just above a wire in which electrons are moving towards east, will point: A) east B) west C) north D) south

Step 1: First, we'll go through the fundamentals of how a magnet works. Simply said, two magnetic fields—the earth's field and the field... View Article

When 10¹⁹ electrons are removed from a neutral metal plate through some process, the charge on it becomes_____________

We are given a situation, we are removing 109 electrons from a neutral metal plate through some unknown process. We must determine the charge... View Article

Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

Given, focal length of a converging lens, f= +20cm, Magnification of image (real) = 2. We know, magnification, m= −v/u ∴... View Article

In a sonometer experiment, the string of length ‘L’ under tension vibrates in a second overtone between two bridges. Where is the amplitude of vibration is maximum at?

The supplied string is L in length and vibrates in the second overtone, therefore n=3, which means it will have two nodes and three antinodes.... View Article

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