VITEEE Physics Test - 7 - JEE MCQ

A parallel plate condenser with oil between the plates (dielectric constant of oil K = 2) has a capacitance C. If the oil is removed, then capacitance of the capacitors becomes

The temperature coefficient of resistivity of material is 0.0004/K. When the temperature of the material is increased by 50 ^oC , its resistivity increases by 2 x 10^-8  ohm -meter. The initial resistivity of the material in ohm-meter is

A microammeter has a resistance of 100 Ω and full scale range of 50 μA. It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination

If the length of the wire is doubled and its area of cross section is decreased to half, then its resistance

The expected energy of the electrons at the absolute zero is called

A transformer is used to light a 100W and 110V lamp from a 220V mains. If the main current is 0.5A, the efficiency of the transformer is approximately

In a current carrying long solenoid, the field produced does not depend upon

Which of the following radiations have the least wavelength?

Two charges -10 C and + 10 C are placed 10cm apart. Potential at the centre of the line joining two charges is

Equal charges are given to two conducting spheres of different radii. The potential will

A charged particle begins to move from the origin in a region which has a uniform magnetic field in the x-direction and a uniform electric field in the y-direction. Its speed is ν, when it reaches the point (x,y,z). The speed (ν) will depend upon

The capacitor of a parallel plate capacitor with no dielectric substance and a separation of 0.4 cm is 2 μF. The separation is reduced to half and it is filled with a substance of dielectric value 2.8. The new capacity of the capacitor is

The path of particle moving under the influence of a force fixed in magnitude and direction is

In radioactive decay process, the negatively charged emitted β -particles are

What is the Q-value of the reaction
p + ⁷Li → ⁴He + ⁴He
The atomic masses of ¹H , ⁴He and ⁷Li are 1.007825 u, 4.002603 u and 7.016004 u respectively

An alpha nucleus of energy 1/2 mv² bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to

Two plane mirrors inclined to each other at an angle 72^o , what is the number of images formed?

The minimum potential difference between the base and emitter required to switch a silicon transistor 'ON' is approximately

Energy gap in a metal is

A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly

In a P-type semiconductor the electrical conduction is due to

In intrinsic semiconductor at room temperature, number of electrons and holes are

The p-n junction diode is used as