Post Test Chapter 1 Physical Quantities and Units
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Name: Class: Date: SMK (L) Methodist Kuala Lumpur STPM Physics Semester 1 Post-Test Chapter 1 Physical Quantities and Units SECTION A 1. The resistive force F acting on a sphere of radius r moving at speed v through a liquid is given by F = cvr where c is a constant. Which of the following is a correct unit for c? A N B N s -1 C N m 2 s -1 D N m -2 s 2. The power P dissipated in s resistor R in which there is a current I is given by P = I 2 R The uncertainty in the value of the resistance is ±10% and the uncertainty in the value of the current is ±3%. The best estimate for the uncertainty of the power dissipated is A ±6% B ±9% C ±16% D ±19% 3. The dimensions of the base quantities of length, mass, time, amount of substance and temperature are denoted by the symbols L, M, T, N and respectively. What are the dimensions of R in the equation pV = nRT? [Dimensions of p: ML -1 T -2 , V:L 3 , n: N, T: ] A ML -2 T -2 -1 B ML 2 T -2 N -1 -1 C MLT -2 N -1 -1 D ML 2 T -2 N -1 -1 4. A student measures the current in a resistor as 677 mA for a potential of 3.6 V. A calculator shows the resistance of the resistor to be 5.3175775 . Which one of the following gives the resistance to an appropriate number of significant figures? A 5.3 B 5.32 C 5.318 D 5.3175775 5. The power dissipated in a resistor of resistance R carrying a current I is equal to I 2 R. The value of I has an uncertainty of ±2% and the value of R has an uncertainty of ±10%. The value of the uncertainty in the calculated power dissipation is A ±8% B ±12% C ±14% D ±20% SECTION B 1. The drag coefficient C D of a car moving with speed v through air of density ρ is given by 1/1
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STPM Physics Term 1
Transcript of Post Test Chapter 1 Physical Quantities and Units
Name: Class: Date:SMK (L) Methodist Kuala Lumpur
STPM Physics Semester 1Post-Test Chapter 1 Physical Quantities and Units
SECTION A
1. The resistive force F acting on a sphere of radius r moving at speed v through a liquid is given byF = cvr
where c is a constant. Which of the following is a correct unit for c?A N B N s-1 C N m2 s-1 D N m-2 s
2. The power P dissipated in s resistor R in which there is a current I is given by P = I2R
The uncertainty in the value of the resistance is ±10% and the uncertainty in the value of the current is ±3%. The best estimate for the uncertainty of the power dissipated isA ±6% B ±9% C ±16% D ±19%
3. The dimensions of the base quantities of length, mass, time, amount of substance and temperature are denoted by the symbols L, M, T, N and respectively. What are the dimensions of R in the equation pV = nRT?[Dimensions of p: ML-1T-2, V:L3, n: N, T: ]A ML-2T-2 -1 B ML2T-2N-1 -1 C MLT-2N-1 -1 D ML2T-2N-1 -1
4. A student measures the current in a resistor as 677 mA for a potential of 3.6 V. A calculator shows the resistance of the resistor to be 5.3175775 . Which one of the following gives the resistance to an appropriate number of significant figures?A 5.3 B 5.32 C 5.318 D 5.3175775
5. The power dissipated in a resistor of resistance R carrying a current I is equal to I2R. The value of I has an uncertainty of ±2% and the value of R has an uncertainty of ±10%. The value of the uncertainty in the calculated power dissipation is A ±8% B ±12% C ±14% D ±20%
SECTION B
1. The drag coefficient CD of a car moving with speed v through air of density ρ is given by
where F is the drag force experienced by the car and A is the maximum cross-sectional area of the car perpendicularly to the direction of travel. Show that CD is dimensionless.
2. (a) Express joule in terms of base units.(b) In high vacuum technology, the theory of gas flow through tubes of small diameter at low pressure is
an important consideration. One equation which is related to this theory is
where k = dimensionless unitr = radius of the tubep1 and p2= pressures at each end of the tube of length lM = molar mass of the gas (unit: kg mol-1)R = molar gas constant (unit: J mol-1 K-1)T = temperature
Use the equation to find the base unit for Q.
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