Units and Measurements

Time periods of oscillation of the same simple pendulum measured using four different measuring clocks were recorded as 4.62 s, 4.632 s, 4.6 s and 4.64 s. The arithmetic mean of these readings in correct significant figure is :

1. 5 s
2. 4.6 s
3. 4.62 s
4. 4.623 s

What is the dimensional formula of ab-1 in the equation (P + aV2 )(V - b) = RT, where letters have their usual meaning.

1. [M6 L7 T4]
2. [ M-1 L5 T3]
3. [ M0 L3 T-2]
4. [ M L2 T-2]

A vernier callipers has 20 divisions on the vernier scale, which coincides with 19th division on the main scale. The least count of the instrument is 0.1 mm. One main scale division is equal to mm.

1. 5
2. 2
3. 1
4. 0.5

The equation of stationary wave is : y=2a ( 2 ) ( 2 x ). Which of the following is NOT correct :

1. The dimensions of nt is [L]
2. The dimensions of n is [ LT-1]
3. The dimensions of x is [L]
4. The dimensions of n/ is [T]

Applying the principle of homogeneity of dimensions, determine which one is correct, where T is time period, G is gravitational constant, M is mass, r is radius of orbit.

1. T2 = 4 2 rGM2
2. T2 = 4 2 r3
3. T2 = 4 2 r3GM
4. T2 = 4 2 r2GM

10 divisions on the main scale of a Vernier calliper coincide with 11 divisions on the Vernier scale. If each division on the main scale is of 5 units, the least count of the instrument is :

1. 511
2. 1011
3. 5011
4. 12

The dimensional formula of angular impulse is :

1. [ ML2T-2]
2. [ ML-2T-1]
3. [ ML2T-1]
4. [ MLT-1]

The radius (r), length (l) and resistance (R) of a metal wire was measured in the laboratory as r=(0.35 0.05) cm R=(100 10) ohm l=(15 0.2) cm The percentage error in resistivity of the material of the wire is :

1. 37.3\%
2. 25.6\%
3. 35.6\%
4. 39.9\%

Match List - I with List - II. Choose the correct answer from the options given below :

1. (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
2. (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
3. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
4. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

If the percentage errors in measuring the length and the diameter of a wire are 0.1\% each. The percentage error in measuring its resistance will be:

1. 0.144%
2. 0.2%
3. 0.1%
4. 0.3%