Identify the correct statements
(A) Electric current arises due to the continuous flow of electrons or ions.
(B) A current flows through a conductor only when there is an electric field within the
conductor.
(C) The drift velocity of electrons is directly proportional to the applied electric field.
(D) The average thermal velocity of the electrons in a conductor is zero.
(E) In the absence of an electric field, the electrons in a conductor are at rest.
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Which of the following statements are correct ?
A. The saturation current is constant with collector plate potential for different frequencies of incident radiation.
B. The saturation current is different with collector plate potential for different frequencies of incident radiation.
C. The saturation current is different with collector plate potential for different intensity of incident radiation.
D. The saturation current is constant with collector plate potential for different intensity of incident radiation.
E. Below threshold frequency no photo electrons are emitted.
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The electric potential at any point in space is given by \( V = 4x^2 \text{ volt} \). The electric field at the point (1 m, 0, 2 m) in SI unit is

AOB is a right angled triangle. Charges \( Q_1 \) and \( Q_2 \) are placed as shown. If the resultant electric field at O is perpendicular to the hypotenuse then \( \frac{Q_1}{Q_2} \) is proportional to :

The magnetic field at a distance r from a long wire carrying current I is 0.4 T. The magnetic field at a distance 2r from the wire is

Identify the correct statements among the following:
(A) The gravitational force is much stronger than the Coulomb force.
(B) The nuclear force between two nucleons falls rapidly to zero as their distance is more than a few femtometers.
(C) The nuclear force depends on the electric charge.
(D) The nuclear force is much stronger than the coulomb force.
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A resistor connected to a battery is heated due to the current. The quantity which does not change is

Cu exist as Cu\(^+\) and Cu\(^{2+}\) ion. Which of the following statements is correct?

The gas evolved when methylamine reacts with nitrous acid is

A bar magnet held perpendicular to a uniform magnetic field experiences a torque \( T_1 \). By what angle should it be rotated to change the experienced torque to \( 0.5T_1 \)?

Mammals are able to survive in Antarctica or in the Sahara desert as they are

In an unbiased p-n junction, holes diffuse from the p-region to n-region because

Let f : R → R be defined as f(x) = [x], where [x] denotes the greatest integer less than or equal to x. Then which of the following statements are correct?
(A) f is one-one but not onto
(B) f is not onto
(C) f is not one-one
(D) f is one-one and onto
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