# Dual Nature of Matter and Radiation (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 11 - 15 of 19

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## Question number: 11

» Dual Nature of Matter and Radiation » Photoelectric Effect

MCQ▾

### Question

The wavelength of the first line of Balmer series is 6134 Å. The wavelength of the first line of Lyman series is –

### Choices

Choice (4) Response

a.

3008 Å

b.

3607 Å

c.

2678 Å

d.

3408 Å

## Question number: 12

» Dual Nature of Matter and Radiation » Einstein's Photoelectric Equation

MCQ▾

### Question

A stream of photons having energy 4.5 eV each impinges on a magnesium surface. The work function of magnesium is 3.66 eV. The emerging photo – electrons are slowed down by copper plates placed 10 mm away. If the potential difference between the two metal plates is 1 V, the maximum distance the electrons can move away from the magnesium surface before being turned back is –

### Choices

Choice (4) Response

a.

8.3 mm

b.

5.0 mm

c.

7.0 mm

d.

3.5 mm

## Question number: 13

» Dual Nature of Matter and Radiation » Photoelectric Effect

MCQ▾

### Question

If the wavelength of photon emitted due to transition of electron from third orbit to first orbit in a hydrogen atom is λ, then the wavelength of photon emitted due to transition of electron from fourth orbit to second orbit will be –

### Choices

Choice (4) Response

a.

b.

c.

d.

## Question number: 14

MCQ▾

### Question

A black body radiates heat energy at the rate of at 1150C. The temperature of the black body, at which the rate of heat radiation is , will be –

### Choices

Choice (4) Response

a.

2730 C

b.

5270 C

c.

8910 C

d.

9270 C

## Question number: 15

» Dual Nature of Matter and Radiation » Photoelectric Effect

Appeared in Year: 2014

MCQ▾

### Question

A 160 watt light source is radiating light of wavelength 6200 Å uniformly in all directions. The photon flux at a distance of 1.8 m is of the order of (Planck’s constant 6.63 × 10–34 J-s)

### Choices

Choice (4) Response

a.

b.

c.

d.

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