# Thermodynamics (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 19 - 22 of 32

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## Question number: 19

» Thermodynamics » Laws of Thermodynamics » First Law of Thermodynamics

MCQ▾

### Question

An ideal gas expands from to at a constant pressure of . The heat energy supplied to the gas in this process is –

### Choices

Choice (4) Response

a.

b.

c.

d.

## Question number: 20

» Thermodynamics » Measurement of Temperature

MCQ▾

### Question

A steel rod (L1 = 10 cm, A1 = 0.02 m2 and k1 = 50 J s-1 m-1 K-1) is welded to a silver rod (L2 = 20 cm, A2 = 0.01 m2, k2 = 400 J s-1 m-1 K-1) as shown in figure below. The ends of the composite rod are maintained at 1500 C and 00 C. The rod is covered with an insulating material so that the heat loss from the sides is negligible. Compute the temperature of the steel-silver junction in the steady state.

### Choices

Choice (4) Response

a.

700 C

b.

1500 C

c.

500 C

d.

1000 C

## Question number: 21

» Thermodynamics » Carnot Engine and Its Efficiency

MCQ▾

### Question

A Carnot engine has efficiency 30 % (heat sink 270 C). To increase efficiency by 20%, the temperature be increased by,

### Choices

Choice (4) Response

a.

40.15 K

b.

15.7 K

c.

20.25 K

d.

55.7 K

## Question number: 22

» Thermodynamics » Measurement of Temperature

Appeared in Year: 2013

MCQ▾

### Question

A metallic prong consists of 4 rods made of the same material, cross-section and same lengths as shown. The three forked ends are kept at 1000 C and the handle end is at 00C. The temperature of the junction is

### Choices

Choice (4) Response

a.

500C

b.

250C

c.

750 C

d.

600 C

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