Atoms — Physics STD 12 Science — Question

Which of the following is a correct statement

(a) Beta rays are same as cathode rays

(b) Gamma rays are high energy neutrons

(c) Alpha particles are singly ionized helium atoms

(d) Protons and neutrons have exactly the same mass

A student plots a graph from his reading on the determination of Young modulus of a metal wire but forgets to put the labels. the quantities on X and Y axes may be respectively:

1. Weight hung and length increased.
2. Stress applied and length Increased.
3. Stress applied and strain developed.
4. Length increased and the weight hung.

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Binding energy per nucleon for C¹² is 7.68 MeV and for C¹³ is 7.74MeV. The energy required to remove a neutron from C¹³ is:

Which type of current is flowing through a circuit?

An electric dipole of moment  p is placed in the position of stable equilibrium in uniform electric field of intensity E. It is rotated through an angle θ from the initial position. The potential energy of electric dipole in the final position is

(a) pEcosθ

(b) pEsinθ

(c) pE(1- cosθ)

(d) -pEcosθ

Dynamo core is laminated because

(a) Magnetic field increases

(b) Magnetic saturation level in core increases

(c) Residual magnetism in core decreases

(d) Loss of energy in core due to eddy currents decreases

The Einstein’s photo-electric equation is based upon the conservation of:

What is the electric field in the cavity of a hollow charged conductor?

In the circuit shown in the figure, the potential difference across the 4.5mF capacitor is

(a)

(b) 4 volts

(c) 6 volts

(d) 8  volts