Summary

Q.

Calculate the dimensional formula for Rydbergs constant.

Q.

The shortest wavelength of X-rays emitted from an X-ray tube depends on the

1. Current in the tube

2. Voltage applied to the tube

3. Nature of gas in the tube

4. Atomic number of target material

Q.

Molybdenum is used as a target element for production of X-rays because it is

1. A heavy element and can easily absorb high velocity electrons

2. A heavy element with a high melting point

3. An element having high thermal conductivity

4. Heavy and can easily deflect electrons

Q.

Hydrogen atom does not emit X-rays because

1. Its energy levels are too close to each other

2. Its energy levels are too apart

3. It is too small in size

4. It has a single electron

Q. If $\overrightarrow{a}=\hat{i}-\hat{j}$ and$\overrightarrow{b}=3\hat{i}+4\hat{j}$, the vector having the same magnitude as $\overrightarrow{b}$ and parallel to $\overrightarrow{a}$ is

1. $\frac{5}{\sqrt{2}}(\hat{i}-\hat{j})$
2. $\frac{5}{\sqrt{2}}(\hat{i}+\hat{j})$
3. $5(\hat{i}-\hat{j})$
4. $5(\hat{i}+\hat{j})$

Q.

X-rays are in nature similar to

1. Beta rays

2. Gamma rays

3. de-Broglie waves

4. Cathode rays

Q.

For continuous X-rays, produced wavelength is

1. Inversely proportional to the energy of the electrons hitting the target

2. Inversely proportional to the intensity of the electron beam

3. Proportional to intensity of the electron beam

4. Proportional to target temperature

Q. A car is moving on a straight horizontal road with a speed $v$. When brakes are applied to give a constant retardation $a$, the car covers distance $S$ before coming to rest. If the car were moving with a speed $3v$ and the same retardation $a$ is applied, the distance that the car travels will be

1. $3S$
2. $6S$
3. $9S$
4. $27S$

Q. X-rays were discovered by?

Q.

The penetrating power of X-rays increases with the

1. Increase in its velocity

2. Increase in its frequency

3. Increase in its intensity

4. Decrease in its velocity

Q. If a negative charge is kept at point $\text{P}$ in the electric field of two charges then it will initially accelerate along

1. $\text{PR}$
2. $\text{PS}$
3. $\text{PQ}$
4. $\text{PT}$

Q. Which of the following property is incorrect?

1. $\hat{a}.\hat{b}$ = $\hat{b}.\hat{a}$
2. $\hat{a}.(\hat{b}+\hat{c})=\hat{a}.\hat{b}+\hat{a}.\hat{c}$
3. $\hat{i}.\hat{j}=\hat{j}.\hat{k}=\hat{k}.\hat{i}=1$
4. $\hat{i}.\hat{i}=\hat{j}.\hat{j}=\hat{k}.\hat{k}=1$

Q. If three ${}^{4}He$ nuclei combine to form a ${}^{12}C$ nucleus, energy is liberated. Why can't helium nuclei combine on their own and minimize the energy?

1. He gas is rare, so collisions between nuclei are also rare;
2. It happens and the ${}^{12}C$ we see in nature was formed by this method only in Earth's atmosphere;
3. The strong nuclear force between nucleons is attractive but short range; the Coulomb force between protons is long range, but repulsive;
4. Helium nucleus is more stable than carbon.

Q. The resultant of two vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ is perpendicular to $\overrightarrow{A}$. Magnitude of resultant $\overrightarrow{R}$ is equal to $\frac{\sqrt{3}}{2}$ times of the magnitude of $\overrightarrow{B}$. Find the angle between $\overrightarrow{A}$ and $\overrightarrow{B}.$

1. ${120}^{\circ }$
2. ${90}^{\circ }$
3. ${60}^{\circ }$
4. ${150}^{\circ }$

Q. The resultant of two vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ is perpendicular to $\overrightarrow{A}$. Magnitude of resultant $\overrightarrow{R}$ is equal to $\frac{\sqrt{3}}{2}$ times of the magnitude of $\overrightarrow{B}$. Find the angle between $\overrightarrow{A}$ and $\overrightarrow{B}.$

1. ${120}^{\circ }$
2. ${90}^{\circ }$
3. ${60}^{\circ }$
4. ${150}^{\circ }$

Q.

The voltage applied across an X-rays tube is nearly

1. 10 V

2. 100 V

3. 10000 V

4. 1000000V

Q. A car is moving on a straight horizontal road with a speed $v$. When brakes are applied to give a constant retardation $a$, the car covers distance $S$ before coming to rest. If the car were moving with a speed $3v$ and the same retardation $a$ is applied, the distance that the car travels will be

1. $3S$
2. $6S$
3. $9S$
4. $27S$

Q.

X-rays are in nature similar to

1. Beta rays

2. Gamma rays

3. de-Broglie waves

4. Cathode rays

Q.

Newton's laws work no matter who you are and how you are moving?

1. True

2. False

Q. If a negative charge is kept at point $\text{P}$ in the electric field of two charges then it will initially accelerate along

1. $\text{PR}$
2. $\text{PS}$
3. $\text{PQ}$
4. $\text{PT}$

Q.

For continuous X-rays, produced wavelength is

1. Inversely proportional to the energy of the electrons hitting the target

2. Inversely proportional to the intensity of the electron beam

3. Proportional to intensity of the electron beam

4. Proportional to target temperature

Q. A car is moving on a straight horizontal road with a speed $v$. When brakes are applied to give a constant retardation $a$, the car covers distance $S$ before coming to rest. If the car were moving with a speed $3v$ and the same retardation $a$ is applied, the distance that the car travels will be

1. $3S$
2. $6S$
3. $9S$
4. $27S$

Q. A muonic atom contains a nucleus of charge Ze and a negative muon, ${\mu }^{-}$, moving about it. The ${\mu }^{-}$ is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass.
Calculate the binding energy of a muonic atom(in eV) with $Z=1$.

Q. If $\overrightarrow{a}=\hat{i}-\hat{j}$ and$\overrightarrow{b}=3\hat{i}+4\hat{j}$, the vector having the same magnitude as $\overrightarrow{b}$ and parallel to $\overrightarrow{a}$ is

1. $\frac{5}{\sqrt{2}}(\hat{i}-\hat{j})$
2. $\frac{5}{\sqrt{2}}(\hat{i}+\hat{j})$
3. $5(\hat{i}-\hat{j})$
4. $5(\hat{i}+\hat{j})$

Q.

Thermal neutrons are those which

1. Are at very high temperature

2. Move with high velocities

3. Have kinetic energies similar to those of surrounding molecules

4. Are at rest

Q.

The electric field due to a charge at a distance of 3 m from it is 500 N/coulomb. The magnitude of the charge is $[\frac{1}{4\pi {ϵ}_0}=9\times {10}^9\frac{N-m^2}{coulom{b}^2}]$

1. 2.5 micro-coulomb

2. 2.0 micro-coulomb

3. 1.0 micro-coulomb

4. 0.5 micro-coulomb

Q.

In radio theraphy, X-rays are used to

1. Detect bone fractures

2. Treat cancer by controlled exposure

3. Detect heart diseases

4. Detect fault in radio receiving circuits