# Class test — I

Subject: Physics

Test: Class test — I

Class: ISC — II, PUC — II

### Question 1

Whats the unit of capacitance?

### Question 2

What is the amount of work done on an equipotential surface?

### Question 3

Between an $\alpha$-particle and a proton which has more energy in a 100-Volt region?

### Question 4

Which is correct for a series combination of capacitance?

(a) $C = C_1+C_2$ (b) $C = \frac{1}{C_1} + \frac{1}{C_2}$ (c) $\frac{1}{C} = \frac{1}{C_1} + \frac{1}{C_2}$.

### Question 5

Electric field intensity $(E =|\vec{E}|)$ for a spherical metallic conductor is

(a) $\frac{\sigma}{\epsilon_0}$ (b) $\frac{2\sigma}{\epsilon_0}$ (c) $\frac{2q\sigma}{\epsilon_0}$.

### Question 6

For a Van de Graaff generator

(a) Outer sphere is at higher potential?

(b) Inner sphere is at higher potential?

### Question 7

Cyclotron frequency

(a) is proportional to energy (b) depends on magnetic field (B)

### Question 8

Angular momentum L is an integral multiple of which constant?

(a) Fine structure constant

(b) Rydberg constant

(c) Universal gas constant

(d) Planck’s constant

### Question 9

Ground state speed of $e^{-}$ in the H-atom in terms of speed-of-light c is

(a) $\frac{c}{137}$ (b) $c\times 137$ (c) $\frac{\alpha\times c}{137}$ (d) $\frac{c}{10}$

### Question 10

Whats the energy of H-atom according to Niels Bohr?

(a) $-\frac{13.61}{n^2}\hspace{2pt}eV$ (b) $+\frac{13.61}{n^2}\hspace{2pt}eV$ (c) $-\frac{13.61}{n}\hspace{2pt}eV$ (d) $-13.61 \hspace{2pt} eV$.

# Class test — II.

Subject: Physics

Test: Class test — II

Class: ISC — II, PUC — II

### Question 1

Which property of the charge is valid?

(a) Charge is a vector quantity

(b) Conservation of quantity of charge

(c) Flux of charge outside a Gaussian surface is conserved.

### Question 2

Which is the drawback of Rutherford’s model?

(a) Atomic instability due to radiative energy loss.

(b) Line spectrum of H-atom is inexplicable.

(c) Can’t explain H-atom.

### Question 3

Which are drawbacks of Bohr’s theory?

(a) Can’t explain Balmer series (b) Can’t explain atomic stability (c) Can’t explain N-spectrum.

### Question 4

Write out the relation between $\epsilon, \epsilon_0, \epsilon_r$.

### Question 5

If dielectric material of dielectric constant K is introduced in a space, which is reduced $E, V \hspace{2pt}or\hspace{2pt}Q$?

### Question 6

Half life of Ra is $x \hspace{2pt} hrs$, of N is $y \hspace{2pt}hrs$, where $x. If we start with 1000 of each which is available in less quantity, after an hour?

### Question 7

Which is used in a nuclear reactor as a moderator material and why?

### Question 8

What is the energy of radiation between H-atom levels, $n = 2, n = 3$?

### Question 9

Write the charge — in units of electron’s charge e, and mass — in units of amu = u, of proton (p) electron (e), $\alpha -{particle}$ and $^{12}C_6$.