KVPY Stream SB-SX (Class 12 & 1st Year BSC) Physics: Questions 209 - 212 of 250

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 250 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 200.00 or

Question number: 209

» Atoms and Nuclei » Energy Levels

MCQ▾

Question

The wavelength of the first Balmer line caused by a transition from the n = 4 level to the n = 2 level in hydrogen is λ1. The wavelength of the line caused by an electronic transition from n = 7 to n = 3 is –

Choices

Choice (4) Response

a.

64016λ1

b.

128375λ1

c.

13238λ1

d.

1323640λ1

Question number: 210

» Physics and Measurement » Accuracy and Precision of Measuring Instruments

MCQ▾

Question

In an experiment, on the measurement of g, using a simple pendulum, the time period was measured with an accuracy of 0.3 % while the length was measured with an accuracy of 0.4%. What is the percentage accuracy in the value of g thus obtained?

Choices

Choice (4) Response

a.

1 %

b.

0.9 %

c.

1.2 %

d.

0.7 %

Question number: 211

» Work, Energy and Power » Conservative and Non-Conservative Forces

Appeared in Year: 2015

MCQ▾

Question

Two small metal balls of different mass m1 and m2 are connected by strings of equal length to fixed point. When the balls are given charges, the angles that the two strings make with the vertical are 300 and 600, respectively. The ratio m1m2 is close to –

Choices

Choice (4) Response

a.

3.0

b.

1.7

c.

0.58

d.

2.0

Question number: 212

» Atoms and Nuclei » Half Life and Mean Life

MCQ▾

Question

A nucleus has a half – life of 45 minutes. At 2: 45 PM its decay rate was measured as 160, 000 counts/sec. What will be the decay rate at 5: 45 PM?

Choices

Choice (4) Response

a.

30, 000countssec

b.

60, 000countssec

c.

10, 000countssec

d.

120, 000countssec

Sign In