Problem set 95

1. Van der Waals equation for one mole is $\left(p+\frac{a}{V^2}\right)(V-b)=RT$. The equation for $n$ moles would be:
1. $\left(p+\frac{an^2}{V^2}\right)(V-nb)=RT$
2. $\left(p+\frac{a^2}{V^2}\right)(V-b)=nRT$
3. $\left(p+\frac{an^2}{V^2}\right)(V-nb)=nRT$
4. $\left(p+\frac{a}{n2V^2}\right)(nV-b)=nRT$

$\left(p+\frac{an^2}{V^2}\right)(V-nb)=nRT$

Hence, answer is (C)

2. A Wheatstone's bridge is used to measure the pressure in the following vacuum gauge:
1. McLeod gauge
2. Pirani gauge
3. Penning gauge
4. Ionization gauge

Pirani gauge

Hence, answer is (B)

3. The continuous X-rays are produced when:
1. Electrons of the target atoms jump from a higher to lower orbital
2. Electrons from the valance electrons are de-excited to the hole in the inner orbitals
3. Electrons are accelerated to fixed energy
4. Incident electrons are deaccelerated near heavy nuclei of the target atoms

Incident electrons are deaccelerated near heavy nuclei of the target atoms

Hence, answer is (D)

4. For detecting photons which of the following detectors is used?
1. Faraday collector
2. Channeltron
3. Photo-multiplier
4. Micro-channel plate

Photo-multiplier

Hence, answer is (C)

5. For obtaining a Laue pattern of a single crystal the sample is held stationary in a beam of :
1. Monochromatic $K_\alpha$ X-rays from Cu target
2. Monochromatic $K_\alpha$ X-rays from Mo target
3. Monochromatic $K_\beta$ X-rays from Cu target
4. Continuous X-rays from any target

Continuous X-rays from any target

Hence, answer is (D)