HSSC physics

The SI unit of capacitance is the:

• 1 Henry
• 2 Coulomb
• 3 Farad
• 4 Ohm

The dimensions of force are:

• 1 ML⁻¹T⁻²
• 2 MLT⁻²
• 3 MLT⁻¹
• 4 ML²T⁻²

The momentum of a 0.5 kg body moving at 4 m/s is:

• 1 8 kg m/s
• 2 4.5 kg m/s
• 3 0.125 kg m/s
• 4 2 kg m/s

The SI unit of resistivity is the:

• 1 Siemens
• 2 Ohm per metre
• 3 Ohm
• 4 Ohm metre

Resistors of 5 Ω and 20 Ω are connected in parallel. The equivalent resistance is:

• 1 4 Ω
• 2 25 Ω
• 3 0.25 Ω
• 4 12.5 Ω

A wave has a frequency of 250 Hz and a wavelength of 1.36 m. Its speed is:

• 1 184 m/s
• 2 0.18 m/s
• 3 340 m/s
• 4 3400 m/s

An object is 30 cm from a convex lens of focal length 10 cm. The image is formed at:

• 1 7.5 cm
• 2 30 cm
• 3 15 cm
• 4 20 cm

A coil of 200 turns links a flux that changes by 0.05 Wb in 0.5 s. The induced emf is:

• 1 100 V
• 2 2 V
• 3 10 V
• 4 20 V

The heat needed to raise the temperature of 2 kg of a substance (c = 500 J/kg K) by 10 K is:

• 1 1000 J
• 2 10000 J
• 3 5000 J
• 4 20000 J

In an isothermal process on an ideal gas, the change in the internal energy is:

• 1 Equal to the work done
• 2 Negative
• 3 Positive
• 4 Zero

Light of photon energy 5 eV falls on a metal of work function 2 eV. The maximum kinetic energy of the electrons is:

• 1 7 eV
• 2 3 eV
• 3 10 eV
• 4 2.5 eV

A sample of 20 g of a radioactive substance goes through 3 half-lives. How much is left?

• 1 6.7 g
• 2 5 g
• 3 10 g
• 4 2.5 g

The force between charges of 3 μC and 4 μC placed 0.3 m apart is (k = 9 × 10⁹ N m²/C²):

• 1 3.6 N
• 2 12 N
• 3 1.2 N
• 4 0.36 N

The energy of the electron in the ground state of the hydrogen atom is:

• 1 −3.4 eV
• 2 −13.6 eV
• 3 13.6 eV
• 4 0 eV

Kirchhoff's first law is based on the conservation of:

• 1 Momentum
• 2 Mass
• 3 Energy
• 4 Charge

At the highest point of its path, a projectile has a vertical velocity that is:

• 1 Negative
• 2 Maximum
• 3 Equal to its horizontal velocity
• 4 Zero

A force of 10 N acts on a 2 kg body at rest through 2 m in its own direction. The kinetic energy gained is:

• 1 10 J
• 2 20 J
• 3 40 J
• 4 5 J

The time period of a simple pendulum of length 0.25 m (g = 9.8 m/s²) is about:

• 1 0.5 s
• 2 2 s
• 3 4 s
• 4 1 s

In a series RLC circuit at resonance, the impedance is equal to:

• 1 The inductive reactance
• 2 The capacitive reactance
• 3 The resistance
• 4 Zero

A force of 20 N acts at right angles to a spanner at 0.3 m from the nut. The torque is:

• 1 23 N m
• 2 0.015 N m
• 3 60 N m
• 4 6 N m

According to Gauss's law, the electric flux through a closed surface depends on:

• 1 The charge outside the surface
• 2 The charge enclosed by the surface
• 3 The size of the surface
• 4 The shape of the surface

The magnetic field near a long straight wire carrying a current varies with the distance r from the wire as:

• 1 1 ÷ r
• 2 r
• 3 r²
• 4 1 ÷ r²

Which of these waves does not need a medium to travel?

• 1 Waves on a string
• 2 Water waves
• 3 Electromagnetic waves
• 4 Sound waves

A rectifier is a device that changes:

• 1 Heat into light
• 2 Direct current into alternating current
• 3 A high voltage into a low voltage
• 4 Alternating current into direct current

The energy equivalent of 1 kg of mass (c = 3 × 10⁸ m/s) is:

• 1 9 × 10⁸ J
• 2 3 × 10⁸ J
• 3 3 × 10¹⁶ J
• 4 9 × 10¹⁶ J