A cube of side 5 cm has a charge of 6 C. The surface density of charge is_________?

A. 100 c m–2
B. 200 c m–2
C. 300 c m–2
D. 400 c m–2

A million electron are added to a pith ball. Its charge is________?

A. – 1.6 × 10–12 coulomb
B. – 1.6 × 10–13 coulomb
C. – 1.6 × 10 –18 coulomb
D. – 1.6 × 10 coulomb

Two identical metal balls with charges + 2Q and – Q are separated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be_________?

A. F
B. F/2
C. F/4
D. F/8

The first overtone of a stretched string of given length is 320 Hz. The first harmonic is_________?

A. 320 hz
B. 640 hz
C. 160 hz
D. 480 hz

What is the ratio of the velocity of sound at 4 atmosphere to that at 1 atmosphere?

A. 4 : 1
B. 1 : 1
C. 2 : 1
D. 1 : 2

The internal energy of the system increases__________?

A. In adiabatic expansion
B. In adiabatic compression
C. In isothermal expansion
D. In isothermal compression

A football is kicked at 45 degrees with horizontal with K.E of E. Its K.E. at highest point is

A. Zero
B. E/2
C. E
D. E/(2)1/2

An object travels at constant speed around a circle of radius 1.0 m in 2.0 seconds. What is the magnitude of its acceleration?

A. 0
B. Π2
C. 2 π2
D. 4 π2

A ball is thrown towards the earth and bounce back. During this process:

A. Direction of velocity and acceleration changes
B. Direction of displacement and acceleration changes
C. Direction of displacement and velocity changes
D. Direction of displacement, velocity and acceleration changes

Potential energy means?

A. Due to position of object
B. Due to motion of object
C. Due to gravity
D. None of these