KVPY Stream SB-SX (Class 12 & 1st Year BSC) Physics: Questions 56 - 59 of 250

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Question number: 56

» Thermodynamics » Measurement of Temperature

Appeared in Year: 2012

MCQ▾

Question

A cylindrical steel rod of length 0.10 m and thermal conductivity 50 Wm-1K-1 is welded end to end to copper rod of thermal conductivity 400 Wm-1K-1 and of the same area of cross section but 0.20 m long. The free end of the steel rod is maintained at 1000C and that of the copper rod at 00C. Assuming that the rods are perfectly insulated from the surrounding the temperature at the junction of the two rods is

Choices

Choice (4) Response
a.

500 C

b.

200 C

c.

400 C

d.

300 C

Question number: 57

» Atoms and Nuclei » Radioactive Decay Law

Appeared in Year: 2012

MCQ▾

Question

A radioactive nucleus A has a single decay mode with half-life τA. Another radioactive nucleus B has two decay modes 1 and 2. If decay mode 2 were absent, the half-life of B would have been τA2 . If decay mode 1 were absent, the half – life of B would have been 3τA . If the actual half – life of B is τB , then the ratio τBτA is –

Choices

Choice (4) Response
a.

73

b.

1

c.

37

d.

72

Question number: 58

» Current Electricity » Electrical Resistance

Appeared in Year: 2011

MCQ▾

Question

The Quantum Hall Resistance RH is a fundamental constant with dimensions of resistance. If h is Planck’s constant and e the electron charge, then the dimension of RH is the same as -

Choices

Choice (4) Response
a.

eh2

b.

he2

c.

h2e

d.

e2h

Question number: 59

» Thermodynamics » Work in Thermodynamic Process and PV Diagrams

Appeared in Year: 2011

MCQ▾

Question

One mole of an ideal gas at initial temperature T, undergoes a quasi-static process during which the volume V is doubled. During the process the internal energy U obeys the equation U=aV3 , where a is a constant. The work done during this process is

Choices

Choice (4) Response
a.

5RT3

b.

5RT2

c.

7RT3

d.

3RT2

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